51640564 has 12 divisors (see below), whose sum is σ = 90457444. Its totient is φ = 25795584.

The previous prime is 51640553. The next prime is 51640571. The reversal of 51640564 is 46504615.

It can be written as a sum of positive squares in 2 ways, for example, as 26440164 + 25200400 = 5142^2 + 5020^2 .

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 987 + ... + 10210.

Almost surely, 2^51640564 is an apocalyptic number.

It is an amenable number.

51640564 is a deficient number, since it is larger than the sum of its proper divisors (38816880).

51640564 is a wasteful number, since it uses less digits than its factorization.

51640564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12354 (or 12352 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 31.

The square root of 51640564 is about 7186.1369316205. The cubic root of 51640564 is about 372.3891272506.

The spelling of 51640564 in words is "fifty-one million, six hundred forty thousand, five hundred sixty-four".