55612561 has 4 divisors (see below), whose sum is σ = 55628352. Its totient is φ = 55596772.

The previous prime is 55612553. The next prime is 55612567. The reversal of 55612561 is 16521655.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16521655 = 5 ⋅3304331.

It is a cyclic number.

It is not a de Polignac number, because 55612561 - 2³ = 55612553 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55612567) 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, 60 + ... + 10546.

It is an arithmetic number, because the mean of its divisors is an integer number (13907088).

Almost surely, 2^55612561 is an apocalyptic number.

It is an amenable number.

55612561 is a deficient number, since it is larger than the sum of its proper divisors (15791).

55612561 is a wasteful number, since it uses less digits than its factorization.

55612561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15790.

The product of its digits is 9000, while the sum is 31.

The square root of 55612561 is about 7457.3829860079. The cubic root of 55612561 is about 381.7018794595.

The spelling of 55612561 in words is "fifty-five million, six hundred twelve thousand, five hundred sixty-one".