56387681 has 6 divisors (see below), whose sum is σ = 65593890. Its totient is φ = 48332256.

The previous prime is 56387677. The next prime is 56387689. The reversal of 56387681 is 18678365.

It can be written as a sum of positive squares in only one way, i.e., 52998400 + 3389281 = 7280^2 + 1841^2 .

It is not a de Polignac number, because 56387681 - 2² = 56387677 is a prime.

It is a super-2 number, since 2×56387681² = 6359141137115522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (56387689) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 575336 + ... + 575433.

It is an arithmetic number, because the mean of its divisors is an integer number (10932315).

Almost surely, 2^56387681 is an apocalyptic number.

It is an amenable number.

56387681 is a deficient number, since it is larger than the sum of its proper divisors (9206209).

56387681 is a wasteful number, since it uses less digits than its factorization.

56387681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1150783 (or 1150776 counting only the distinct ones).

The product of its digits is 241920, while the sum is 44.

The square root of 56387681 is about 7509.1731235869. The cubic root of 56387681 is about 383.4670725956.

The spelling of 56387681 in words is "fifty-six million, three hundred eighty-seven thousand, six hundred eighty-one".