51231965085 has 384 divisors, whose sum is σ = 120191385600. Its totient is φ = 19617914880.

The previous prime is 51231965077. The next prime is 51231965101. The reversal of 51231965085 is 58056913215.

51231965085 is a `hidden beast` number, since 5 + 123 + 19 + 6 + 508 + 5 = 666.

It is not a de Polignac number, because 51231965085 - 2³ = 51231965077 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 51231965085.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 116701296 + ... + 116701734.

It is an arithmetic number, because the mean of its divisors is an integer number (312998400).

Almost surely, 2^51231965085 is an apocalyptic number.

It is an amenable number.

51231965085 is an abundant number, since it is smaller than the sum of its proper divisors (68959420515).

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

51231965085 is a wasteful number, since it uses less digits than its factorization.

51231965085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 561 (or 558 counting only the distinct ones).

The product of its (nonzero) digits is 324000, while the sum is 45.

The spelling of 51231965085 in words is "fifty-one billion, two hundred thirty-one million, nine hundred sixty-five thousand, eighty-five".