51656537 has 4 divisors (see below), whose sum is σ = 51804900. Its totient is φ = 51508176.

The previous prime is 51656533. The next prime is 51656543. The reversal of 51656537 is 73565615.

51656537 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 21307456 + 30349081 = 4616^2 + 5509^2 .

It is a cyclic number.

It is not a de Polignac number, because 51656537 - 2² = 51656533 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51656537.

It is not an unprimeable number, because it can be changed into a prime (51656533) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 73658 + ... + 74355.

It is an arithmetic number, because the mean of its divisors is an integer number (12951225).

Almost surely, 2^51656537 is an apocalyptic number.

It is an amenable number.

51656537 is a deficient number, since it is larger than the sum of its proper divisors (148363).

51656537 is a wasteful number, since it uses less digits than its factorization.

51656537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148362.

The product of its digits is 94500, while the sum is 38.

The square root of 51656537 is about 7187.2482216771. The cubic root of 51656537 is about 372.4275179903.

The spelling of 51656537 in words is "fifty-one million, six hundred fifty-six thousand, five hundred thirty-seven".