56660155561 has 4 divisors (see below), whose sum is σ = 57377372800. Its totient is φ = 55942938324.

The previous prime is 56660155553. The next prime is 56660155571. The reversal of 56660155561 is 16555106665.

56660155561 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, and also an emirpimes, since its reverse is a distinct semiprime: 16555106665 = 5 ⋅3311021333.

It is a cyclic number.

It is not a de Polignac number, because 56660155561 - 2³ = 56660155553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (56660155571) 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, 358608501 + ... + 358608658.

It is an arithmetic number, because the mean of its divisors is an integer number (14344343200).

Almost surely, 2^56660155561 is an apocalyptic number.

It is an amenable number.

56660155561 is a deficient number, since it is larger than the sum of its proper divisors (717217239).

56660155561 is an equidigital number, since it uses as much as digits as its factorization.

56660155561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 717217238.

The product of its (nonzero) digits is 810000, while the sum is 46.

The spelling of 56660155561 in words is "fifty-six billion, six hundred sixty million, one hundred fifty-five thousand, five hundred sixty-one".