56120721 has 16 divisors (see below), whose sum is σ = 76581120. Its totient is φ = 36547200.

The previous prime is 56120717. The next prime is 56120747. The reversal of 56120721 is 12702165.

It is not a de Polignac number, because 56120721 - 2² = 56120717 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 56120691 and 56120700.

It is not an unprimeable number, because it can be changed into a prime (56120711) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22696 + ... + 25046.

It is an arithmetic number, because the mean of its divisors is an integer number (4786320).

Almost surely, 2^56120721 is an apocalyptic number.

It is an amenable number.

56120721 is a deficient number, since it is larger than the sum of its proper divisors (20460399).

56120721 is a wasteful number, since it uses less digits than its factorization.

56120721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2536.

The product of its (nonzero) digits is 840, while the sum is 24.

The square root of 56120721 is about 7491.3764422835. The cubic root of 56120721 is about 382.8609570569.

Adding to 56120721 its reverse (12702165), we get a palindrome (68822886).

The spelling of 56120721 in words is "fifty-six million, one hundred twenty thousand, seven hundred twenty-one".