51321564 has 36 divisors (see below), whose sum is σ = 148263024. Its totient is φ = 14663232.

The previous prime is 51321551. The next prime is 51321577. The reversal of 51321564 is 46512315.

It is an interprime number because it is at equal distance from previous prime (51321551) and next prime (51321577).

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 101577 + ... + 102080.

Almost surely, 2^51321564 is an apocalyptic number.

It is an amenable number.

51321564 is an abundant number, since it is smaller than the sum of its proper divisors (96941460).

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

51321564 is a wasteful number, since it uses less digits than its factorization.

51321564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203674 (or 203669 counting only the distinct ones).

The product of its digits is 3600, while the sum is 27.

The square root of 51321564 is about 7163.9070345727. The cubic root of 51321564 is about 371.6207546720.

Adding to 51321564 its reverse (46512315), we get a palindrome (97833879).

Subtracting from 51321564 its reverse (46512315), we obtain a square (4809249 = 2193²).

The spelling of 51321564 in words is "fifty-one million, three hundred twenty-one thousand, five hundred sixty-four".