56531721 has 8 divisors (see below), whose sum is σ = 75755200. Its totient is φ = 37498032.

The previous prime is 56531687. The next prime is 56531737. The reversal of 56531721 is 12713565.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 56531721 - 2¹³ = 56523529 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 (56531621) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46750 + ... + 47943.

It is an arithmetic number, because the mean of its divisors is an integer number (9469400).

Almost surely, 2^56531721 is an apocalyptic number.

It is an amenable number.

56531721 is a deficient number, since it is larger than the sum of its proper divisors (19223479).

56531721 is a wasteful number, since it uses less digits than its factorization.

56531721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94895.

The product of its digits is 6300, while the sum is 30.

The square root of 56531721 is about 7518.7579426392. The cubic root of 56531721 is about 383.7933118929.

The spelling of 56531721 in words is "fifty-six million, five hundred thirty-one thousand, seven hundred twenty-one".