51638840 has 32 divisors (see below), whose sum is σ = 126750960. Its totient is φ = 18777600.

The previous prime is 51638833. The next prime is 51638861. The reversal of 51638840 is 4883615.

51638840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 51638840.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 58241 + ... + 59120.

Almost surely, 2^51638840 is an apocalyptic number.

It is an amenable number.

51638840 is an abundant number, since it is smaller than the sum of its proper divisors (75112120).

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

51638840 is a wasteful number, since it uses less digits than its factorization.

51638840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117383 (or 117379 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 35.

The square root of 51638840 is about 7186.0169774361. The cubic root of 51638840 is about 372.3849831828.

The spelling of 51638840 in words is "fifty-one million, six hundred thirty-eight thousand, eight hundred forty".