55191888 has 80 divisors (see below), whose sum is σ = 159364800. Its totient is φ = 18288000.

The previous prime is 55191883. The next prime is 55191923. The reversal of 55191888 is 88819155.

55191888 is a `hidden beast` number, since 551 + 9 + 18 + 88 = 666.

It is a super-2 number, since 2×55191888² = 6092289002009088, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55191883) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 108178 + ... + 108686.

It is an arithmetic number, because the mean of its divisors is an integer number (1992060).

Almost surely, 2^55191888 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55191888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79682400).

55191888 is an abundant number, since it is smaller than the sum of its proper divisors (104172912).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

55191888 is a wasteful number, since it uses less digits than its factorization.

55191888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 777 (or 765 counting only the distinct ones).

The product of its digits is 115200, while the sum is 45.

The square root of 55191888 is about 7429.1243090959. The cubic root of 55191888 is about 380.7369999702.

The spelling of 55191888 in words is "fifty-five million, one hundred ninety-one thousand, eight hundred eighty-eight".