55561800 has 96 divisors (see below), whose sum is σ = 196862400. Its totient is φ = 12698880.

The previous prime is 55561787. The next prime is 55561837. The reversal of 55561800 is 816555.

It is a happy number.

It is a super-2 number, since 2×55561800² = 6174227238480000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2415 + ... + 10814.

It is an arithmetic number, because the mean of its divisors is an integer number (2050650).

Almost surely, 2^55561800 is an apocalyptic number.

55561800 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55561800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98431200).

55561800 is an abundant number, since it is smaller than the sum of its proper divisors (141300600).

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

55561800 is a wasteful number, since it uses less digits than its factorization.

55561800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13255 (or 13246 counting only the distinct ones).

The product of its (nonzero) digits is 6000, while the sum is 30.

The square root of 55561800 is about 7453.9788032969. The cubic root of 55561800 is about 381.5857098578.

The spelling of 55561800 in words is "fifty-five million, five hundred sixty-one thousand, eight hundred".