72138 has 16 divisors (see below), whose sum is σ = 157536. Its totient is φ = 21840.

The previous prime is 72109. The next prime is 72139. The reversal of 72138 is 83127.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 72138.

It is not an unprimeable number, because it can be changed into a prime (72139) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 481 + ... + 612.

It is an arithmetic number, because the mean of its divisors is an integer number (9846).

2⁷²¹³⁸ is an apocalyptic number.

72138 is an abundant number, since it is smaller than the sum of its proper divisors (85398).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (78768).

72138 is a wasteful number, since it uses less digits than its factorization.

72138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1109.

The product of its digits is 336, while the sum is 21.

The square root of 72138 is about 268.5851820187. The cubic root of 72138 is about 41.6282383470.

It can be divided in two parts, 72 and 138, that added together give a triangular number (210 = T₂₀).

The spelling of 72138 in words is "seventy-two thousand, one hundred thirty-eight".