51138072 has 48 divisors (see below), whose sum is σ = 139361040. Its totient is φ = 16939968.

The previous prime is 51138071. The next prime is 51138079. The reversal of 51138072 is 27083115.

51138072 is a `hidden beast` number, since 511 + 3 + 80 + 72 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51138071) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9898 + ... + 14150.

It is an arithmetic number, because the mean of its divisors is an integer number (2903355).

Almost surely, 2^51138072 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51138072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (69680520).

51138072 is an abundant number, since it is smaller than the sum of its proper divisors (88222968).

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

51138072 is a wasteful number, since it uses less digits than its factorization.

51138072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4432 (or 4425 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 51138072 is about 7151.0888681375. The cubic root of 51138072 is about 371.1773357087.

It can be divided in two parts, 511 and 38072, that added together give a palindrome (38583).

The spelling of 51138072 in words is "fifty-one million, one hundred thirty-eight thousand, seventy-two".