56221561 has 12 divisors (see below), whose sum is σ = 62097700. Its totient is φ = 50862240.

The previous prime is 56221553. The next prime is 56221579. The reversal of 56221561 is 16512265.

It can be written as a sum of positive squares in 2 ways, for example, as 54479161 + 1742400 = 7381^2 + 1320^2 .

It is not a de Polignac number, because 56221561 - 2³ = 56221553 is a prime.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56221531) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 26695 + ... + 28723.

Almost surely, 2^56221561 is an apocalyptic number.

It is an amenable number.

56221561 is a deficient number, since it is larger than the sum of its proper divisors (5876139).

56221561 is a wasteful number, since it uses less digits than its factorization.

56221561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2280 (or 2269 counting only the distinct ones).

The product of its digits is 3600, while the sum is 28.

The square root of 56221561 is about 7498.1038269685. The cubic root of 56221561 is about 383.0901332406.

The spelling of 56221561 in words is "fifty-six million, two hundred twenty-one thousand, five hundred sixty-one".