56815861 has 4 divisors (see below), whose sum is σ = 56959372. Its totient is φ = 56672352.

The previous prime is 56815859. The next prime is 56815867. The reversal of 56815861 is 16851865.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12180100 + 44635761 = 3490^2 + 6681^2 .

It is a cyclic number.

It is not a de Polignac number, because 56815861 - 2¹ = 56815859 is a prime.

It is a super-2 number, since 2×56815861² = 6456084122342642, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56815867) 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, 71160 + ... + 71953.

It is an arithmetic number, because the mean of its divisors is an integer number (14239843).

Almost surely, 2^56815861 is an apocalyptic number.

It is an amenable number.

56815861 is a deficient number, since it is larger than the sum of its proper divisors (143511).

56815861 is a wasteful number, since it uses less digits than its factorization.

56815861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143510.

The product of its digits is 57600, while the sum is 40.

The square root of 56815861 is about 7537.6296672097. The cubic root of 56815861 is about 384.4352455065.

The spelling of 56815861 in words is "fifty-six million, eight hundred fifteen thousand, eight hundred sixty-one".