The total was the highest in the competition, surpassing the previous best of 398-5 by Sri Lanka against Kenya at Kandy in the 1996 World Cup.
Hard-hitting opener Sehwag, who had just one half-century in his previous 14 games, smashed an 87-ball 114 with three sixes and 17 fours for his eighth hundred - his first in two years.
The 28-year-old opener shared a 202-run stand for the second wicket with in-form Sourav Ganguly (89).
Ganguly, who scored 66 in his team's below-par batting performance against Bangladesh, extended his impressive run with yet another solid knock. He struck two sixes and three fours in his 114-ball knock.
He looked set to become the first batsman to score five centuries in the World Cup when he was stumped attempting a big shot. Australians Ricky Ponting and Mark Waugh, and Indian Sachin Tendulkar are others with four hundreds.
India, keeping an eye on the net run-rate their losing their opening match, sent in big-hitters Mahendra Dhoni and Yuvraj Singh ahead of Sachin Tendulkar. The move paid off as runs came thick and fast. The innings contained 18 sixes.
Dhoni hit a 25-ball 29 and Yuvraj an explosive 46-ball 83 with seven sixes. Yuvraj and Tendulkar added 122 for the fifth wicket off just 62 balls. Tendulkar made a 29-ball 57 not out with four sixes.
India, in a must-win situation after being upset by Bangladesh in their previous game, found the going easy against against Bermuda who looked clueless after early second-over celebrations.
New-ball bowler Malachi Jones, at 17 one of the youngest cricketers in the tournament, struck with his first delivery when he had opener Robin Uthappa caught by burly Dwayne Leverock, who dived to his right to hold the ball.
The Bermudian cricketers celebrated the early success as if they had taken more than just a wicket. But the joy was short-lived as their attack was soon put to the sword by Sehwag.
The opener made the most of the opportunity of regaining form against the weakest team in the four-team group, dominating the seamers and spinners with a wide range of attractive shots.
Sehwag outscored Ganguly, racing to his half-century off 43 balls with 11 fours. He took 38 more deliveries to complete his century, with a single off seamer Kevin Hurdle.
He fell playing shots, caught by Jones at mid-off off Hurdle while trying to clear the ground. But India had vritually batted Bermuda out of the match at the stage.
Sri Lanka and Bangladesh have posted one victory in the group, while India and Bermuda are winless after one game. Sri Lanka beat Bermuda by 243 runs in their opening match.
India 413 for 5 in 50 overs (Sehwag 114, Yuvraj 83, Ganguly 89, Tendulkar 57 n o, Dhoni 29; Borden 2 for 30, Hurdle 1 for 53) Vs Bermuda (yet to bat)