55511621 has 4 divisors (see below), whose sum is σ = 60558144. Its totient is φ = 50465100.

The previous prime is 55511611. The next prime is 55511623. The reversal of 55511621 is 12611555.

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 55511621 - 2⁶ = 55511557 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 (55511623) 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, 2523245 + ... + 2523266.

It is an arithmetic number, because the mean of its divisors is an integer number (15139536).

Almost surely, 2^55511621 is an apocalyptic number.

It is an amenable number.

55511621 is a deficient number, since it is larger than the sum of its proper divisors (5046523).

55511621 is a wasteful number, since it uses less digits than its factorization.

55511621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5046522.

The product of its digits is 1500, while the sum is 26.

The square root of 55511621 is about 7450.6121225038. The cubic root of 55511621 is about 381.4708026349.

The spelling of 55511621 in words is "fifty-five million, five hundred eleven thousand, six hundred twenty-one".