138537 has 16 divisors (see below), whose sum is σ = 234880. Its totient is φ = 79056.

The previous prime is 138517. The next prime is 138547. The reversal of 138537 is 735831.

It is not a de Polignac number, because 138537 - 2¹⁵ = 105769 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an Ulam number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 138537.

It is not an unprimeable number, because it can be changed into a prime (138517) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 178 + ... + 555.

It is an arithmetic number, because the mean of its divisors is an integer number (14680).

2¹³⁸⁵³⁷ is an apocalyptic number.

It is an amenable number.

138537 is a deficient number, since it is larger than the sum of its proper divisors (96343).

138537 is an equidigital number, since it uses as much as digits as its factorization.

138537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 749 (or 743 counting only the distinct ones).

The product of its digits is 2520, while the sum is 27.

The square root of 138537 is about 372.2055883514. The cubic root of 138537 is about 51.7434354202.

The spelling of 138537 in words is "one hundred thirty-eight thousand, five hundred thirty-seven".