51425490681 has 20 divisors (see below), whose sum is σ = 78270250212. Its totient is φ = 33636796128.

The previous prime is 51425490667. The next prime is 51425490709. The reversal of 51425490681 is 18609452415.

51425490681 is a `hidden beast` number, since 5 + 1 + 42 + 549 + 0 + 68 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 33445094400 + 17980396281 = 182880^2 + 134091^2 .

It is not a de Polignac number, because 51425490681 - 2⁷ = 51425490553 is a prime.

It is a super-2 number, since 2×51425490681² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (51425490601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 5985166 + ... + 5993751.

Almost surely, 2^51425490681 is an apocalyptic number.

It is an amenable number.

51425490681 is a deficient number, since it is larger than the sum of its proper divisors (26844759531).

51425490681 is a wasteful number, since it uses less digits than its factorization.

51425490681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11978982 (or 11978973 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 45.

The spelling of 51425490681 in words is "fifty-one billion, four hundred twenty-five million, four hundred ninety thousand, six hundred eighty-one".