56577218261 has 4 divisors (see below), whose sum is σ = 56579769900. Its totient is φ = 56574666624.

The previous prime is 56577218239. The next prime is 56577218281. The reversal of 56577218261 is 16281277565.

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 31641650161 + 24935568100 = 177881^2 + 157910^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-56577218261 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56577218281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1242266 + ... + 1287003.

It is an arithmetic number, because the mean of its divisors is an integer number (14144942475).

Almost surely, 2^56577218261 is an apocalyptic number.

It is an amenable number.

56577218261 is a deficient number, since it is larger than the sum of its proper divisors (2551639).

56577218261 is a wasteful number, since it uses less digits than its factorization.

56577218261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2551638.

The product of its digits is 1411200, while the sum is 50.

The spelling of 56577218261 in words is "fifty-six billion, five hundred seventy-seven million, two hundred eighteen thousand, two hundred sixty-one".