51381800 has 48 divisors (see below), whose sum is σ = 120156000. Its totient is φ = 20433600.

The previous prime is 51381797. The next prime is 51381809. The reversal of 51381800 is 818315.

It is a self number, because there is not a number n which added to its sum of digits gives 51381800.

It is not an unprimeable number, because it can be changed into a prime (51381809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 39155 + ... + 40445.

It is an arithmetic number, because the mean of its divisors is an integer number (2503250).

Almost surely, 2^51381800 is an apocalyptic number.

51381800 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 51381800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (60078000).

51381800 is an abundant number, since it is smaller than the sum of its proper divisors (68774200).

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

51381800 is a wasteful number, since it uses less digits than its factorization.

51381800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1506 (or 1497 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 26.

The square root of 51381800 is about 7168.1099321927. The cubic root of 51381800 is about 371.7660879655.

The spelling of 51381800 in words is "fifty-one million, three hundred eighty-one thousand, eight hundred".