56561557 has 4 divisors (see below), whose sum is σ = 60912460. Its totient is φ = 52210656.

The previous prime is 56561521. The next prime is 56561563. The reversal of 56561557 is 75516565.

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 31820881 + 24740676 = 5641^2 + 4974^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-56561557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56561507) 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, 2175432 + ... + 2175457.

It is an arithmetic number, because the mean of its divisors is an integer number (15228115).

Almost surely, 2^56561557 is an apocalyptic number.

It is an amenable number.

56561557 is a deficient number, since it is larger than the sum of its proper divisors (4350903).

56561557 is a wasteful number, since it uses less digits than its factorization.

56561557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4350902.

The product of its digits is 157500, while the sum is 40.

The square root of 56561557 is about 7520.7417852231. The cubic root of 56561557 is about 383.8608187908.

The spelling of 56561557 in words is "fifty-six million, five hundred sixty-one thousand, five hundred fifty-seven".