56561357581 has 4 divisors (see below), whose sum is σ = 56673806112. Its totient is φ = 56448909052.

The previous prime is 56561357497. The next prime is 56561357591. The reversal of 56561357581 is 18575316565.

56561357581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 56561357581 - 2¹³ = 56561349389 is a prime.

It is a super-2 number, since 2×56561357581² (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 (56561357591) 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, 56223511 + ... + 56224516.

It is an arithmetic number, because the mean of its divisors is an integer number (14168451528).

Almost surely, 2^56561357581 is an apocalyptic number.

It is an amenable number.

56561357581 is a deficient number, since it is larger than the sum of its proper divisors (112448531).

56561357581 is a wasteful number, since it uses less digits than its factorization.

56561357581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112448530.

The product of its digits is 3780000, while the sum is 52.

The spelling of 56561357581 in words is "fifty-six billion, five hundred sixty-one million, three hundred fifty-seven thousand, five hundred eighty-one".