56531921 has 4 divisors (see below), whose sum is σ = 56622144. Its totient is φ = 56441700.

The previous prime is 56531887. The next prime is 56531939. The reversal of 56531921 is 12913565.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 56531921 - 2¹⁸ = 56269777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (56531621) 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, 44165 + ... + 45426.

It is an arithmetic number, because the mean of its divisors is an integer number (14155536).

Almost surely, 2^56531921 is an apocalyptic number.

It is an amenable number.

56531921 is a deficient number, since it is larger than the sum of its proper divisors (90223).

56531921 is an equidigital number, since it uses as much as digits as its factorization.

56531921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90222.

The product of its digits is 8100, while the sum is 32.

The square root of 56531921 is about 7518.7712426965. The cubic root of 56531921 is about 383.7937644917.

The spelling of 56531921 in words is "fifty-six million, five hundred thirty-one thousand, nine hundred twenty-one".