51656585 has 4 divisors (see below), whose sum is σ = 61987908. Its totient is φ = 41325264.

The previous prime is 51656543. The next prime is 51656593. The reversal of 51656585 is 58565615.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 58565615 = 5 ⋅11713123.

It can be written as a sum of positive squares in 2 ways, for example, as 40819321 + 10837264 = 6389^2 + 3292^2 .

It is a cyclic number.

It is not a de Polignac number, because 51656585 - 2¹⁰ = 51655561 is a prime.

It is a Duffinian 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, 5165654 + ... + 5165663.

It is an arithmetic number, because the mean of its divisors is an integer number (15496977).

Almost surely, 2^51656585 is an apocalyptic number.

It is an amenable number.

51656585 is a deficient number, since it is larger than the sum of its proper divisors (10331323).

51656585 is a wasteful number, since it uses less digits than its factorization.

51656585 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10331322.

The product of its digits is 180000, while the sum is 41.

The square root of 51656585 is about 7187.2515609237. The cubic root of 51656585 is about 372.4276333453.

The spelling of 51656585 in words is "fifty-one million, six hundred fifty-six thousand, five hundred eighty-five".