721165964 has 12 divisors (see below), whose sum is σ = 1296149904. Its totient is φ = 350837424.

The previous prime is 721165903. The next prime is 721165981. The reversal of 721165964 is 469561127.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2436224 + ... + 2436519.

It is an arithmetic number, because the mean of its divisors is an integer number (108012492).

Almost surely, 2^721165964 is an apocalyptic number.

721165964 is a gapful number since it is divisible by the number (74) formed by its first and last digit.

It is an amenable number.

721165964 is a deficient number, since it is larger than the sum of its proper divisors (574983940).

721165964 is a wasteful number, since it uses less digits than its factorization.

721165964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4872784 (or 4872782 counting only the distinct ones).

The product of its digits is 90720, while the sum is 41.

The square root of 721165964 is about 26854.5333975476. The cubic root of 721165964 is about 896.7644991826.

The spelling of 721165964 in words is "seven hundred twenty-one million, one hundred sixty-five thousand, nine hundred sixty-four".