51979940 has 24 divisors (see below), whose sum is σ = 110789952. Its totient is φ = 20481120.

The previous prime is 51979937. The next prime is 51979951. The reversal of 51979940 is 4997915.

It is a junction number, because it is equal to n+sod(n) for n = 51979891 and 51979900.

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 7 ways as a sum of consecutive naturals, for example, 18056 + ... + 20735.

It is an arithmetic number, because the mean of its divisors is an integer number (4616248).

Almost surely, 2^51979940 is an apocalyptic number.

It is an amenable number.

51979940 is an abundant number, since it is smaller than the sum of its proper divisors (58810012).

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

51979940 is a wasteful number, since it uses less digits than its factorization.

51979940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38867 (or 38865 counting only the distinct ones).

The product of its (nonzero) digits is 102060, while the sum is 44.

The square root of 51979940 is about 7209.7115060174. The cubic root of 51979940 is about 373.2031132433.

The spelling of 51979940 in words is "fifty-one million, nine hundred seventy-nine thousand, nine hundred forty".