51512295681 has 64 divisors (see below), whose sum is σ = 95776051200. Its totient is φ = 26582256000.

The previous prime is 51512295641. The next prime is 51512295811. The reversal of 51512295681 is 18659221515.

51512295681 is a `hidden beast` number, since 5 + 1 + 512 + 2 + 9 + 56 + 81 = 666.

It is not a de Polignac number, because 51512295681 - 2⁶ = 51512295617 is a prime.

It is a super-2 number, since 2×51512295681² (a number of 22 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (51512295631) by changing a digit.

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 63 ways as a sum of consecutive naturals, for example, 231885 + ... + 395973.

It is an arithmetic number, because the mean of its divisors is an integer number (1496500800).

Almost surely, 2^51512295681 is an apocalyptic number.

It is an amenable number.

51512295681 is a deficient number, since it is larger than the sum of its proper divisors (44263755519).

51512295681 is a wasteful number, since it uses less digits than its factorization.

51512295681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164267 (or 164261 counting only the distinct ones).

The product of its digits is 216000, while the sum is 45.

The spelling of 51512295681 in words is "fifty-one billion, five hundred twelve million, two hundred ninety-five thousand, six hundred eighty-one".