51860816640 has 216 divisors, whose sum is σ = 181025470080. Its totient is φ = 13706821632.

The previous prime is 51860816633. The next prime is 51860816653. The reversal of 51860816640 is 4661806815.

51860816640 is a `hidden beast` number, since 518 + 60 + 8 + 16 + 64 + 0 = 666.

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 (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1281841 + ... + 1321679.

It is an arithmetic number, because the mean of its divisors is an integer number (838080880).

Almost surely, 2^51860816640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51860816640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90512735040).

51860816640 is an abundant number, since it is smaller than the sum of its proper divisors (129164653440).

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

51860816640 is a wasteful number, since it uses less digits than its factorization.

51860816640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39979 (or 39962 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 45.

The spelling of 51860816640 in words is "fifty-one billion, eight hundred sixty million, eight hundred sixteen thousand, six hundred forty".