56605591 has 4 divisors (see below), whose sum is σ = 64692112. Its totient is φ = 48519072.

The previous prime is 56605589. The next prime is 56605609. The reversal of 56605591 is 19550665.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19550665 = 5 ⋅3910133.

It is not a de Polignac number, because 56605591 - 2¹ = 56605589 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 56605591.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56605511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4043250 + ... + 4043263.

It is an arithmetic number, because the mean of its divisors is an integer number (16173028).

Almost surely, 2^56605591 is an apocalyptic number.

56605591 is a deficient number, since it is larger than the sum of its proper divisors (8086521).

56605591 is an equidigital number, since it uses as much as digits as its factorization.

56605591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8086520.

The product of its (nonzero) digits is 40500, while the sum is 37.

The square root of 56605591 is about 7523.6687194480. The cubic root of 56605591 is about 383.9604067070.

The spelling of 56605591 in words is "fifty-six million, six hundred five thousand, five hundred ninety-one".