138520 has 16 divisors (see below), whose sum is σ = 311760. Its totient is φ = 55392.

The previous prime is 138517. The next prime is 138547. The reversal of 138520 is 25831.

138520 = 89² + 90² + ... + 103².

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1692 + ... + 1771.

It is an arithmetic number, because the mean of its divisors is an integer number (19485).

2¹³⁸⁵²⁰ is an apocalyptic number.

138520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138520 is an abundant number, since it is smaller than the sum of its proper divisors (173240).

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

138520 is a wasteful number, since it uses less digits than its factorization.

138520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3474 (or 3470 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 138520 is about 372.1827508093. The cubic root of 138520 is about 51.7413188391.

The spelling of 138520 in words is "one hundred thirty-eight thousand, five hundred twenty".