51138500 has 96 divisors (see below), whose sum is σ = 134534400. Its totient is φ = 16588800.

The previous prime is 51138469. The next prime is 51138539. The reversal of 51138500 is 583115.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 66116 + ... + 66884.

It is an arithmetic number, because the mean of its divisors is an integer number (1401400).

Almost surely, 2^51138500 is an apocalyptic number.

51138500 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 51138500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (67267200).

51138500 is an abundant number, since it is smaller than the sum of its proper divisors (83395900).

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

51138500 is a wasteful number, since it uses less digits than its factorization.

51138500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 814 (or 802 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 23.

The square root of 51138500 is about 7151.1187935875. The cubic root of 51138500 is about 371.1783712285.

The spelling of 51138500 in words is "fifty-one million, one hundred thirty-eight thousand, five hundred".