31124560365721 has 9 divisors (see below), whose sum is σ = 31723197891679. Its totient is φ = 30537014404936.

The previous prime is 31124560365677. The next prime is 31124560365761. The reversal of 31124560365721 is 12756306542113.

The square root of 31124560365721 is 5578939.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 22437605817225 + 8686954548496 = 4736835^2 + 2947364^2 .

It is not a de Polignac number, because 31124560365721 - 2³⁹ = 30574804551833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31124560365761) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 295631136 + ... + 295736398.

Almost surely, 2^{31124560365721} is an apocalyptic number.

31124560365721 is the 5578939-th square number.

31124560365721 is the 2789470-th centered octagonal number.

It is an amenable number.

31124560365721 is a deficient number, since it is larger than the sum of its proper divisors (598637525958).

31124560365721 is an frugal number, since it uses more digits than its factorization.

31124560365721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210632 (or 105316 counting only the distinct ones).

The product of its (nonzero) digits is 907200, while the sum is 46.

The spelling of 31124560365721 in words is "thirty-one trillion, one hundred twenty-four billion, five hundred sixty million, three hundred sixty-five thousand, seven hundred twenty-one".