138540 has 24 divisors (see below), whose sum is σ = 388080. Its totient is φ = 36928.

The previous prime is 138517. The next prime is 138547. The reversal of 138540 is 45831.

It is not an unprimeable number, because it can be changed into a prime (138547) 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, 1095 + ... + 1214.

It is an arithmetic number, because the mean of its divisors is an integer number (16170).

2¹³⁸⁵⁴⁰ is an apocalyptic number.

138540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138540 is an abundant number, since it is smaller than the sum of its proper divisors (249540).

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

138540 is a wasteful number, since it uses less digits than its factorization.

138540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2321 (or 2319 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 138540 is about 372.2096183604. The cubic root of 138540 is about 51.7438089165.

The spelling of 138540 in words is "one hundred thirty-eight thousand, five hundred forty".