721331272 has 32 divisors (see below), whose sum is σ = 1382012280. Its totient is φ = 352834560.

The previous prime is 721331263. The next prime is 721331291. The reversal of 721331272 is 272133127.

It is a happy number.

721331272 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 640798596 + 80532676 = 25314^2 + 8974^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 721331272.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 155872 + ... + 160432.

Almost surely, 2^721331272 is an apocalyptic number.

It is an amenable number.

721331272 is a deficient number, since it is larger than the sum of its proper divisors (660681008).

721331272 is a wasteful number, since it uses less digits than its factorization.

721331272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4993 (or 4989 counting only the distinct ones).

The product of its digits is 3528, while the sum is 28.

The square root of 721331272 is about 26857.6110627881. The cubic root of 721331272 is about 896.8330137030.

Adding to 721331272 its reverse (272133127), we get a palindrome (993464399).

The spelling of 721331272 in words is "seven hundred twenty-one million, three hundred thirty-one thousand, two hundred seventy-two".