721560864 has 24 divisors (see below), whose sum is σ = 1894097520. Its totient is φ = 240520256.

The previous prime is 721560863. The next prime is 721560871. The reversal of 721560864 is 468065127.

It is a tau number, because it is divible by the number of its divisors (24).

It is not an unprimeable number, because it can be changed into a prime (721560863) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3758034 + ... + 3758225.

It is an arithmetic number, because the mean of its divisors is an integer number (78920730).

Almost surely, 2^721560864 is an apocalyptic number.

It is an amenable number.

721560864 is an abundant number, since it is smaller than the sum of its proper divisors (1172536656).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

721560864 is a wasteful number, since it uses less digits than its factorization.

721560864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7516272 (or 7516264 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 39.

The square root of 721560864 is about 26861.8849673659. The cubic root of 721560864 is about 896.9281543831.

The spelling of 721560864 in words is "seven hundred twenty-one million, five hundred sixty thousand, eight hundred sixty-four".