138623 has 4 divisors (see below), whose sum is σ = 140760. Its totient is φ = 136488.

The previous prime is 138617. The next prime is 138629. The reversal of 138623 is 326831.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (138617) and next prime (138629).

It is a cyclic number.

It is not a de Polignac number, because 138623 - 2⁶ = 138559 is a prime.

It is a super-2 number, since 2×138623² = 38432672258, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138629) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 968 + ... + 1101.

It is an arithmetic number, because the mean of its divisors is an integer number (35190).

2¹³⁸⁶²³ is an apocalyptic number.

138623 is a deficient number, since it is larger than the sum of its proper divisors (2137).

138623 is an equidigital number, since it uses as much as digits as its factorization.

138623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2136.

The product of its digits is 864, while the sum is 23.

The square root of 138623 is about 372.3210979786. The cubic root of 138623 is about 51.7541401777.

It can be divided in two parts, 1386 and 23, that multiplied together give a triangular number (31878 = T₂₅₂).

The spelling of 138623 in words is "one hundred thirty-eight thousand, six hundred twenty-three".