51251664 has 40 divisors (see below), whose sum is σ = 139371040. Its totient is φ = 16184448.

The previous prime is 51251647. The next prime is 51251687. The reversal of 51251664 is 46615215.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27187 + ... + 29010.

It is an arithmetic number, because the mean of its divisors is an integer number (3484276).

Almost surely, 2^51251664 is an apocalyptic number.

It is an amenable number.

51251664 is an abundant number, since it is smaller than the sum of its proper divisors (88119376).

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

51251664 is a wasteful number, since it uses less digits than its factorization.

51251664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56227 (or 56221 counting only the distinct ones).

The product of its digits is 7200, while the sum is 30.

The square root of 51251664 is about 7159.0267494961. The cubic root of 51251664 is about 371.4519621223.

Adding to 51251664 its reverse (46615215), we get a palindrome (97866879).

It can be divided in two parts, 51251 and 664, that added together give a palindrome (51915).

The spelling of 51251664 in words is "fifty-one million, two hundred fifty-one thousand, six hundred sixty-four".