56591921 has 4 divisors (see below), whose sum is σ = 56720112. Its totient is φ = 56463732.

The previous prime is 56591917. The next prime is 56591959. The reversal of 56591921 is 12919565.

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 56591921 - 2² = 56591917 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (56591971) 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, 63431 + ... + 64316.

It is an arithmetic number, because the mean of its divisors is an integer number (14180028).

Almost surely, 2^56591921 is an apocalyptic number.

It is an amenable number.

56591921 is a deficient number, since it is larger than the sum of its proper divisors (128191).

56591921 is a wasteful number, since it uses less digits than its factorization.

56591921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128190.

The product of its digits is 24300, while the sum is 38.

The square root of 56591921 is about 7522.7601982251. The cubic root of 56591921 is about 383.9294959716.

The spelling of 56591921 in words is "fifty-six million, five hundred ninety-one thousand, nine hundred twenty-one".