51918390 has 48 divisors (see below), whose sum is σ = 135343728. Its totient is φ = 13808448.

The previous prime is 51918371. The next prime is 51918401. The reversal of 51918390 is 9381915.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 65577 + ... + 66363.

It is an arithmetic number, because the mean of its divisors is an integer number (2819661).

Almost surely, 2^51918390 is an apocalyptic number.

51918390 is an abundant number, since it is smaller than the sum of its proper divisors (83425338).

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

51918390 is a wasteful number, since it uses less digits than its factorization.

51918390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1533 (or 1530 counting only the distinct ones).

The product of its (nonzero) digits is 9720, while the sum is 36.

The square root of 51918390 is about 7205.4416936091. The cubic root of 51918390 is about 373.0557504710.

The spelling of 51918390 in words is "fifty-one million, nine hundred eighteen thousand, three hundred ninety".