51685415838 has 48 divisors (see below), whose sum is σ = 128000411136. Its totient is φ = 14765245200.

The previous prime is 51685415819. The next prime is 51685415863. The reversal of 51685415838 is 83851458615.

51685415838 is a `hidden beast` number, since 5 + 1 + 6 + 8 + 54 + 1 + 583 + 8 = 666.

It is a congruent number.

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 23 ways as a sum of consecutive naturals, for example, 1067863 + ... + 1115213.

It is an arithmetic number, because the mean of its divisors is an integer number (2666675232).

Almost surely, 2^51685415838 is an apocalyptic number.

51685415838 is an abundant number, since it is smaller than the sum of its proper divisors (76314995298).

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

51685415838 is a wasteful number, since it uses less digits than its factorization.

51685415838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56029 (or 56026 counting only the distinct ones).

The product of its digits is 4608000, while the sum is 54.

The spelling of 51685415838 in words is "fifty-one billion, six hundred eighty-five million, four hundred fifteen thousand, eight hundred thirty-eight".