51561051156 has 18 divisors (see below), whose sum is σ = 130334879402. Its totient is φ = 17187017040.

The previous prime is 51561051131. The next prime is 51561051163. The reversal of 51561051156 is 65115016515.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 51560784900 + 266256 = 227070^2 + 516^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 1432251421 = 51561051156 / (5 + 1 + 5 + 6 + 1 + 0 + 5 + 1 + 1 + 5 + 6).

It is a self number, because there is not a number n which added to its sum of digits gives 51561051156.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 716125675 + ... + 716125746.

Almost surely, 2^51561051156 is an apocalyptic number.

It is an amenable number.

51561051156 is an abundant number, since it is smaller than the sum of its proper divisors (78773828246).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51561051156 is a wasteful number, since it uses less digits than its factorization.

51561051156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1432251431 (or 1432251426 counting only the distinct ones).

The product of its (nonzero) digits is 22500, while the sum is 36.

The spelling of 51561051156 in words is "fifty-one billion, five hundred sixty-one million, fifty-one thousand, one hundred fifty-six".