56556806581 has 8 divisors (see below), whose sum is σ = 61700730624. Its totient is φ = 51413281920.

The previous prime is 56556806479. The next prime is 56556806597. The reversal of 56556806581 is 18560865565.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-56556806581 is a prime.

It is a super-2 number, since 2×56556806581² (a number of 22 digits) 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 (56556809581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 249381 + ... + 418693.

It is an arithmetic number, because the mean of its divisors is an integer number (7712591328).

Almost surely, 2^56556806581 is an apocalyptic number.

It is an amenable number.

56556806581 is a deficient number, since it is larger than the sum of its proper divisors (5143924043).

56556806581 is a wasteful number, since it uses less digits than its factorization.

56556806581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199691.

The product of its (nonzero) digits is 8640000, while the sum is 55.

The spelling of 56556806581 in words is "fifty-six billion, five hundred fifty-six million, eight hundred six thousand, five hundred eighty-one".