56615661 has 48 divisors (see below), whose sum is σ = 90805104. Its totient is φ = 33841152.

The previous prime is 56615639. The next prime is 56615677. The reversal of 56615661 is 16651665.

It can be written as a sum of positive squares in 8 ways, for example, as 10850436 + 45765225 = 3294^2 + 6765^2 .

It is not a de Polignac number, because 56615661 - 2¹⁰ = 56614637 is a prime.

Its product of digits (32400) is a multiple of the sum of its prime factors (270).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56615681) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 413185 + ... + 413321.

It is an arithmetic number, because the mean of its divisors is an integer number (1891773).

Almost surely, 2^56615661 is an apocalyptic number.

56615661 is a gapful number since it is divisible by the number (51) formed by its first and last digit.

It is an amenable number.

56615661 is a deficient number, since it is larger than the sum of its proper divisors (34189443).

56615661 is a wasteful number, since it uses less digits than its factorization.

56615661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270 (or 267 counting only the distinct ones).

The product of its digits is 32400, while the sum is 36.

The square root of 56615661 is about 7524.3379110723. The cubic root of 56615661 is about 383.9831739047.

The spelling of 56615661 in words is "fifty-six million, six hundred fifteen thousand, six hundred sixty-one".