55765621 has 4 divisors (see below), whose sum is σ = 57564544. Its totient is φ = 53966700.

The previous prime is 55765609. The next prime is 55765667. The reversal of 55765621 is 12656755.

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.

It is a cyclic number.

It is not a de Polignac number, because 55765621 - 2¹⁷ = 55634549 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 (55765691) 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, 899415 + ... + 899476.

It is an arithmetic number, because the mean of its divisors is an integer number (14391136).

Almost surely, 2^55765621 is an apocalyptic number.

It is an amenable number.

55765621 is a deficient number, since it is larger than the sum of its proper divisors (1798923).

55765621 is a wasteful number, since it uses less digits than its factorization.

55765621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1798922.

The product of its digits is 63000, while the sum is 37.

The square root of 55765621 is about 7467.6382477996. The cubic root of 55765621 is about 382.0517391064.

The spelling of 55765621 in words is "fifty-five million, seven hundred sixty-five thousand, six hundred twenty-one".