37656561 has 4 divisors (see below), whose sum is σ = 50208752. Its totient is φ = 25104372.

The previous prime is 37656533. The next prime is 37656569. The reversal of 37656561 is 16565673.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16565673 = 3 ⋅5521891.

It is not a de Polignac number, because 37656561 - 2¹⁴ = 37640177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (37656569) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6276091 + ... + 6276096.

It is an arithmetic number, because the mean of its divisors is an integer number (12552188).

Almost surely, 2^37656561 is an apocalyptic number.

It is an amenable number.

37656561 is a deficient number, since it is larger than the sum of its proper divisors (12552191).

37656561 is a wasteful number, since it uses less digits than its factorization.

37656561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12552190.

The product of its digits is 113400, while the sum is 39.

The square root of 37656561 is about 6136.4941945707. The cubic root of 37656561 is about 335.1816375936.

The spelling of 37656561 in words is "thirty-seven million, six hundred fifty-six thousand, five hundred sixty-one".