51618920 has 32 divisors (see below), whose sum is σ = 118847520. Its totient is φ = 20166720.

The previous prime is 51618913. The next prime is 51618943. The reversal of 51618920 is 2981615.

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, 13286 + ... + 16725.

It is an arithmetic number, because the mean of its divisors is an integer number (3713985).

Almost surely, 2^51618920 is an apocalyptic number.

It is an amenable number.

51618920 is an abundant number, since it is smaller than the sum of its proper divisors (67228600).

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

51618920 is a wasteful number, since it uses less digits than its factorization.

51618920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30065 (or 30061 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 32.

The square root of 51618920 is about 7184.6308186294. The cubic root of 51618920 is about 372.3370937588.

The spelling of 51618920 in words is "fifty-one million, six hundred eighteen thousand, nine hundred twenty".