56561616 has 60 divisors (see below), whose sum is σ = 159902340. Its totient is φ = 18662400.

The previous prime is 56561563. The next prime is 56561621. The reversal of 56561616 is 61616565.

It can be written as a sum of positive squares in 2 ways, for example, as 48944016 + 7617600 = 6996^2 + 2760^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12600 + ... + 16488.

It is an arithmetic number, because the mean of its divisors is an integer number (2665039).

Almost surely, 2^56561616 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 56561616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79951170).

56561616 is an abundant number, since it is smaller than the sum of its proper divisors (103340724).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

56561616 is a wasteful number, since it uses less digits than its factorization.

56561616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4004 (or 3995 counting only the distinct ones).

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

The square root of 56561616 is about 7520.7457077074. The cubic root of 56561616 is about 383.8609522606.

The spelling of 56561616 in words is "fifty-six million, five hundred sixty-one thousand, six hundred sixteen".