51861918 has 32 divisors (see below), whose sum is σ = 111974400. Its totient is φ = 15964256.

The previous prime is 51861911. The next prime is 51861919. The reversal of 51861918 is 81916815.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51861911) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2478 + ... + 10481.

It is an arithmetic number, because the mean of its divisors is an integer number (3499200).

Almost surely, 2^51861918 is an apocalyptic number.

51861918 is a gapful number since it is divisible by the number (58) formed by its first and last digit.

51861918 is an abundant number, since it is smaller than the sum of its proper divisors (60112482).

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

51861918 is a wasteful number, since it uses less digits than its factorization.

51861918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13016.

The product of its digits is 17280, while the sum is 39.

The square root of 51861918 is about 7201.5219224828. The cubic root of 51861918 is about 372.9204429414.

The spelling of 51861918 in words is "fifty-one million, eight hundred sixty-one thousand, nine hundred eighteen".