55621565 has 16 divisors (see below), whose sum is σ = 69465600. Its totient is φ = 42702912.

The previous prime is 55621561. The next prime is 55621627. The reversal of 55621565 is 56512655.

It is a cyclic number.

It is not a de Polignac number, because 55621565 - 2² = 55621561 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55621561) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24884 + ... + 27026.

It is an arithmetic number, because the mean of its divisors is an integer number (4341600).

Almost surely, 2^55621565 is an apocalyptic number.

It is an amenable number.

55621565 is a deficient number, since it is larger than the sum of its proper divisors (13844035).

55621565 is a wasteful number, since it uses less digits than its factorization.

55621565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2356.

The product of its digits is 45000, while the sum is 35.

The square root of 55621565 is about 7457.9866586097. The cubic root of 55621565 is about 381.7224782727.

The spelling of 55621565 in words is "fifty-five million, six hundred twenty-one thousand, five hundred sixty-five".