55871521 has 4 divisors (see below), whose sum is σ = 55915200. Its totient is φ = 55827844.

The previous prime is 55871509. The next prime is 55871549. The reversal of 55871521 is 12517855.

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 55871521 - 2⁹ = 55871009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55871551) 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, 19861 + ... + 22498.

It is an arithmetic number, because the mean of its divisors is an integer number (13978800).

Almost surely, 2^55871521 is an apocalyptic number.

It is an amenable number.

55871521 is a deficient number, since it is larger than the sum of its proper divisors (43679).

55871521 is a wasteful number, since it uses less digits than its factorization.

55871521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43678.

The product of its digits is 14000, while the sum is 34.

The square root of 55871521 is about 7474.7254799089. The cubic root of 55871521 is about 382.2934274109.

The spelling of 55871521 in words is "fifty-five million, eight hundred seventy-one thousand, five hundred twenty-one".