51656510665 has 16 divisors (see below), whose sum is σ = 63322115328. Its totient is φ = 40436102016.

The previous prime is 51656510657. The next prime is 51656510671. The reversal of 51656510665 is 56601565615.

It is a cyclic number.

It is not a de Polignac number, because 51656510665 - 2³ = 51656510657 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1028989 + ... + 1078021.

It is an arithmetic number, because the mean of its divisors is an integer number (3957632208).

Almost surely, 2^51656510665 is an apocalyptic number.

It is an amenable number.

51656510665 is a deficient number, since it is larger than the sum of its proper divisors (11665604663).

51656510665 is a wasteful number, since it uses less digits than its factorization.

51656510665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53568.

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

The spelling of 51656510665 in words is "fifty-one billion, six hundred fifty-six million, five hundred ten thousand, six hundred sixty-five".