55185921 has 32 divisors (see below), whose sum is σ = 96460800. Its totient is φ = 30514320.

The previous prime is 55185917. The next prime is 55185931. The reversal of 55185921 is 12958155.

It is a happy number.

55185921 is a `hidden beast` number, since 55 + 18 + 592 + 1 = 666.

It is not a de Polignac number, because 55185921 - 2² = 55185917 is a prime.

It is not an unprimeable number, because it can be changed into a prime (55185931) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1150 + ... + 10568.

It is an arithmetic number, because the mean of its divisors is an integer number (3014400).

Almost surely, 2^55185921 is an apocalyptic number.

It is an amenable number.

55185921 is a deficient number, since it is larger than the sum of its proper divisors (41274879).

55185921 is a wasteful number, since it uses less digits than its factorization.

55185921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9466 (or 9460 counting only the distinct ones).

The product of its digits is 18000, while the sum is 36.

The square root of 55185921 is about 7428.7227031301. The cubic root of 55185921 is about 380.7232785119.

The spelling of 55185921 in words is "fifty-five million, one hundred eighty-five thousand, nine hundred twenty-one".