51800400 has 90 divisors (see below), whose sum is σ = 179774270. Its totient is φ = 13812480.

The previous prime is 51800389. The next prime is 51800401. The reversal of 51800400 is 400815.

It can be written as a sum of positive squares in 3 ways, for example, as 992016 + 50808384 = 996^2 + 7128^2 .

It is a tau number, because it is divible by the number of its divisors (90).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51800401) by changing a digit.

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 17 ways as a sum of consecutive naturals, for example, 3595 + ... + 10794.

Almost surely, 2^51800400 is an apocalyptic number.

51800400 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

51800400 is an abundant number, since it is smaller than the sum of its proper divisors (127973870).

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

51800400 is a wasteful number, since it uses less digits than its factorization.

51800400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14413 (or 14399 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 51800400 is about 7197.2494746257. The cubic root of 51800400 is about 372.7729333134.

The spelling of 51800400 in words is "fifty-one million, eight hundred thousand, four hundred".