55188909 has 12 divisors (see below), whose sum is σ = 81571776. Its totient is φ = 35936712.

The previous prime is 55188899. The next prime is 55188923. The reversal of 55188909 is 90988155.

55188909 is a `hidden beast` number, since 551 + 8 + 8 + 90 + 9 = 666.

It is not a de Polignac number, because 55188909 - 2¹² = 55184813 is a prime.

It is a super-2 number, since 2×55188909² = 6091631353220562, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55188979) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 70917 + ... + 71690.

It is an arithmetic number, because the mean of its divisors is an integer number (6797648).

Almost surely, 2^55188909 is an apocalyptic number.

It is an amenable number.

55188909 is a deficient number, since it is larger than the sum of its proper divisors (26382867).

55188909 is a wasteful number, since it uses less digits than its factorization.

55188909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142656 (or 142653 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 45.

The square root of 55188909 is about 7428.9238116971. The cubic root of 55188909 is about 380.7301497127.

The spelling of 55188909 in words is "fifty-five million, one hundred eighty-eight thousand, nine hundred nine".