56111561 has 8 divisors (see below), whose sum is σ = 62515584. Its totient is φ = 49924720.

The previous prime is 56111533. The next prime is 56111591. The reversal of 56111561 is 16511165.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-56111561 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 56111561.

It is not an unprimeable number, because it can be changed into a prime (56111591) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53750 + ... + 54783.

It is an arithmetic number, because the mean of its divisors is an integer number (7814448).

Almost surely, 2^56111561 is an apocalyptic number.

It is an amenable number.

56111561 is a deficient number, since it is larger than the sum of its proper divisors (6404023).

56111561 is a wasteful number, since it uses less digits than its factorization.

56111561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108591.

The product of its digits is 900, while the sum is 26.

The square root of 56111561 is about 7490.7650477104. The cubic root of 56111561 is about 382.8401257898.

The spelling of 56111561 in words is "fifty-six million, one hundred eleven thousand, five hundred sixty-one".