51397918938 has 24 divisors (see below), whose sum is σ = 111615847200. Its totient is φ = 17093610504.

The previous prime is 51397918937. The next prime is 51397918961. The reversal of 51397918938 is 83981979315.

51397918938 is a `hidden beast` number, since 51 + 397 + 91 + 89 + 38 = 666.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (51397918931) 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 11 ways as a sum of consecutive naturals, for example, 3244308 + ... + 3260111.

It is an arithmetic number, because the mean of its divisors is an integer number (4650660300).

Almost surely, 2^51397918938 is an apocalyptic number.

51397918938 is an abundant number, since it is smaller than the sum of its proper divisors (60217928262).

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

51397918938 is a wasteful number, since it uses less digits than its factorization.

51397918938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6504866 (or 6504863 counting only the distinct ones).

The product of its digits is 14696640, while the sum is 63.

The spelling of 51397918938 in words is "fifty-one billion, three hundred ninety-seven million, nine hundred eighteen thousand, nine hundred thirty-eight".