55188880 has 40 divisors (see below), whose sum is σ = 129511800. Its totient is φ = 21869568.

The previous prime is 55188871. The next prime is 55188899. The reversal of 55188880 is 8888155.

It can be written as a sum of positive squares in 4 ways, for example, as 15649936 + 39538944 = 3956^2 + 6288^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a Smith number, since the sum of its digits (43) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5556 + ... + 11884.

It is an arithmetic number, because the mean of its divisors is an integer number (3237795).

Almost surely, 2^55188880 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 55188880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (64755900).

55188880 is an abundant number, since it is smaller than the sum of its proper divisors (74322920).

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

55188880 is a wasteful number, since it uses less digits than its factorization.

55188880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6451 (or 6445 counting only the distinct ones).

The product of its (nonzero) digits is 102400, while the sum is 43.

The square root of 55188880 is about 7428.9218598663. The cubic root of 55188880 is about 380.7300830255.

It can be divided in two parts, 55188 and 880, that multiplied together give a triangular number (48565440 = T₉₈₅₅).

The spelling of 55188880 in words is "fifty-five million, one hundred eighty-eight thousand, eight hundred eighty".