138705 has 16 divisors (see below), whose sum is σ = 253824. Its totient is φ = 63360.

The previous prime is 138683. The next prime is 138727. The reversal of 138705 is 507831.

138705 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (138683) and next prime (138727).

It is not a de Polignac number, because 138705 - 2⁶ = 138641 is a prime.

It is a Curzon number.

138705 is a lucky number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 556 + ... + 765.

It is an arithmetic number, because the mean of its divisors is an integer number (15864).

2¹³⁸⁷⁰⁵ is an apocalyptic number.

138705 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

138705 is a deficient number, since it is larger than the sum of its proper divisors (115119).

138705 is a wasteful number, since it uses less digits than its factorization.

138705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1336.

The product of its (nonzero) digits is 840, while the sum is 24.

The square root of 138705 is about 372.4312017004. The cubic root of 138705 is about 51.7643429170.

The spelling of 138705 in words is "one hundred thirty-eight thousand, seven hundred five".