138615 has 8 divisors (see below), whose sum is σ = 221808. Its totient is φ = 73920.

The previous prime is 138599. The next prime is 138617. The reversal of 138615 is 516831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 138615 - 2⁴ = 138599 is a prime.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

138615 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4606 + ... + 4635.

It is an arithmetic number, because the mean of its divisors is an integer number (27726).

2¹³⁸⁶¹⁵ is an apocalyptic number.

138615 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

138615 is a deficient number, since it is larger than the sum of its proper divisors (83193).

138615 is an equidigital number, since it uses as much as digits as its factorization.

138615 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9249.

The product of its digits is 720, while the sum is 24.

The square root of 138615 is about 372.3103544088. The cubic root of 138615 is about 51.7531445731.

The spelling of 138615 in words is "one hundred thirty-eight thousand, six hundred fifteen".