56105561 has 4 divisors (see below), whose sum is σ = 56120592. Its totient is φ = 56090532.

The previous prime is 56105551. The next prime is 56105573. The reversal of 56105561 is 16550165.

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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 56105561 - 2¹⁰ = 56104537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (56105501) 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, 2846 + ... + 10968.

It is an arithmetic number, because the mean of its divisors is an integer number (14030148).

Almost surely, 2^56105561 is an apocalyptic number.

It is an amenable number.

56105561 is a deficient number, since it is larger than the sum of its proper divisors (15031).

56105561 is an equidigital number, since it uses as much as digits as its factorization.

56105561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15030.

The product of its (nonzero) digits is 4500, while the sum is 29.

The square root of 56105561 is about 7490.3645438657. The cubic root of 56105561 is about 382.8264796261.

The spelling of 56105561 in words is "fifty-six million, one hundred five thousand, five hundred sixty-one".