55120400 has 60 divisors (see below), whose sum is σ = 135697044. Its totient is φ = 21504000.

The previous prime is 55120399. The next prime is 55120423. The reversal of 55120400 is 402155.

It can be written as a sum of positive squares in 6 ways, for example, as 4596736 + 50523664 = 2144^2 + 7108^2 .

It is a congruent number.

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, 14720 + ... + 18080.

Almost surely, 2^55120400 is an apocalyptic number.

55120400 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 55120400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (67848522).

55120400 is an abundant number, since it is smaller than the sum of its proper divisors (80576644).

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

55120400 is a wasteful number, since it uses less digits than its factorization.

55120400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3420 (or 3409 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 17.

The square root of 55120400 is about 7424.3114158823. The cubic root of 55120400 is about 380.5725441196.

Adding to 55120400 its reverse (402155), we get a palindrome (55522555).

The spelling of 55120400 in words is "fifty-five million, one hundred twenty thousand, four hundred".