138724 has 12 divisors (see below), whose sum is σ = 246400. Its totient is φ = 68328.

The previous prime is 138683. The next prime is 138727. The reversal of 138724 is 427831.

138724 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (138727) by changing a digit.

138724 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 97 + ... + 535.

2¹³⁸⁷²⁴ is an apocalyptic number.

It is an amenable number.

138724 is a deficient number, since it is larger than the sum of its proper divisors (107676).

138724 is a wasteful number, since it uses less digits than its factorization.

138724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 522 (or 520 counting only the distinct ones).

The product of its digits is 1344, while the sum is 25.

The square root of 138724 is about 372.4567088938. The cubic root of 138724 is about 51.7667063925.

The spelling of 138724 in words is "one hundred thirty-eight thousand, seven hundred twenty-four".