721408831 has 8 divisors (see below), whose sum is σ = 847529424. Its totient is φ = 605377920.

The previous prime is 721408829. The next prime is 721408847. The reversal of 721408831 is 138804127.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 721408831 - 2¹ = 721408829 is a prime.

It is a super-2 number, since 2×721408831² = 1040861402889573122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721408801) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2522266 + ... + 2522551.

It is an arithmetic number, because the mean of its divisors is an integer number (105941178).

Almost surely, 2^721408831 is an apocalyptic number.

721408831 is a deficient number, since it is larger than the sum of its proper divisors (126120593).

721408831 is a wasteful number, since it uses less digits than its factorization.

721408831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5044841.

The product of its (nonzero) digits is 10752, while the sum is 34.

The square root of 721408831 is about 26859.0549163592. The cubic root of 721408831 is about 896.8651556520.

The spelling of 721408831 in words is "seven hundred twenty-one million, four hundred eight thousand, eight hundred thirty-one".