55661800 has 48 divisors (see below), whose sum is σ = 130125600. Its totient is φ = 22142400.

The previous prime is 55661797. The next prime is 55661813. The reversal of 55661800 is 816655.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 41541 + ... + 42859.

It is an arithmetic number, because the mean of its divisors is an integer number (2710950).

Almost surely, 2^55661800 is an apocalyptic number.

55661800 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 55661800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (65062800).

55661800 is an abundant number, since it is smaller than the sum of its proper divisors (74463800).

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

55661800 is a wasteful number, since it uses less digits than its factorization.

55661800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1546 (or 1537 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 31.

The square root of 55661800 is about 7460.6836147903. The cubic root of 55661800 is about 381.8144983497.

The spelling of 55661800 in words is "fifty-five million, six hundred sixty-one thousand, eight hundred".