51605566565 has 32 divisors (see below), whose sum is σ = 72634848000. Its totient is φ = 34460826624.

The previous prime is 51605566561. The next prime is 51605566567. The reversal of 51605566565 is 56566550615.

51605566565 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 51605566565 - 2² = 51605566561 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51605566561) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 456311 + ... + 558059.

It is an arithmetic number, because the mean of its divisors is an integer number (2269839000).

Almost surely, 2^51605566565 is an apocalyptic number.

It is an amenable number.

51605566565 is a deficient number, since it is larger than the sum of its proper divisors (21029281435).

51605566565 is a wasteful number, since it uses less digits than its factorization.

51605566565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102141.

The product of its (nonzero) digits is 4050000, while the sum is 50.

The spelling of 51605566565 in words is "fifty-one billion, six hundred five million, five hundred sixty-six thousand, five hundred sixty-five".