56715721 has 4 divisors (see below), whose sum is σ = 56847744. Its totient is φ = 56583700.

The previous prime is 56715719. The next prime is 56715733. The reversal of 56715721 is 12751765.

It is a happy number.

56715721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 56715721 - 2¹ = 56715719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (56715761) 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 3 ways as a sum of consecutive naturals, for example, 65365 + ... + 66226.

It is an arithmetic number, because the mean of its divisors is an integer number (14211936).

Almost surely, 2^56715721 is an apocalyptic number.

It is an amenable number.

56715721 is a deficient number, since it is larger than the sum of its proper divisors (132023).

56715721 is a wasteful number, since it uses less digits than its factorization.

56715721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132022.

The product of its digits is 14700, while the sum is 34.

The square root of 56715721 is about 7530.9840658443. The cubic root of 56715721 is about 384.2092523617.

The spelling of 56715721 in words is "fifty-six million, seven hundred fifteen thousand, seven hundred twenty-one".