51312400 has 60 divisors (see below), whose sum is σ = 124191952. Its totient is φ = 20373120.

The previous prime is 51312353. The next prime is 51312403. The reversal of 51312400 is 421315.

51312400 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is not an unprimeable number, because it can be changed into a prime (51312403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 64807 + ... + 65593.

Almost surely, 2^51312400 is an apocalyptic number.

51312400 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 51312400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (62095976).

51312400 is an abundant number, since it is smaller than the sum of its proper divisors (72879552).

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

51312400 is a wasteful number, since it uses less digits than its factorization.

51312400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 968 (or 957 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 51312400 is about 7163.2674108957. The cubic root of 51312400 is about 371.5986344361.

Adding to 51312400 its reverse (421315), we get a palindrome (51733715).

The spelling of 51312400 in words is "fifty-one million, three hundred twelve thousand, four hundred".