51506295840 has 72 divisors (see below), whose sum is σ = 175765239468. Its totient is φ = 13735011840.

The previous prime is 51506295839. The next prime is 51506295889. The reversal of 51506295840 is 4859260515.

51506295840 is a `hidden beast` number, since 5 + 1 + 5 + 0 + 62 + 9 + 584 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 51182727696 + 323568144 = 226236^2 + 17988^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×51506295840² (a number of 22 digits) contains 22 as substring.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17882691 + ... + 17885570.

Almost surely, 2^51506295840 is an apocalyptic number.

It is an amenable number.

51506295840 is an abundant number, since it is smaller than the sum of its proper divisors (124258943628).

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

51506295840 is a wasteful number, since it uses less digits than its factorization.

51506295840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35768282 (or 35768271 counting only the distinct ones).

The product of its (nonzero) digits is 432000, while the sum is 45.

The spelling of 51506295840 in words is "fifty-one billion, five hundred six million, two hundred ninety-five thousand, eight hundred forty".