561264921 has 24 divisors (see below), whose sum is σ = 975299520. Its totient is φ = 303842016.

The previous prime is 561264887. The next prime is 561264931. The reversal of 561264921 is 129462165.

561264921 is a `hidden beast` number, since 5 + 6 + 1 + 2 + 649 + 2 + 1 = 666.

It is not a de Polignac number, because 561264921 - 2⁶ = 561264857 is a prime.

It is not an unprimeable number, because it can be changed into a prime (561264931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 233250 + ... + 235643.

It is an arithmetic number, because the mean of its divisors is an integer number (40637480).

Almost surely, 2^561264921 is an apocalyptic number.

It is an amenable number.

561264921 is a deficient number, since it is larger than the sum of its proper divisors (414034599).

561264921 is a wasteful number, since it uses less digits than its factorization.

561264921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 468925 (or 468922 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 561264921 is about 23691.0303912683. The cubic root of 561264921 is about 824.8772004552.

The spelling of 561264921 in words is "five hundred sixty-one million, two hundred sixty-four thousand, nine hundred twenty-one".