138731823 has 12 divisors (see below), whose sum is σ = 205278528. Its totient is φ = 90231840.

The previous prime is 138731807. The next prime is 138731839. The reversal of 138731823 is 328137831.

It is an interprime number because it is at equal distance from previous prime (138731807) and next prime (138731839).

It is not a de Polignac number, because 138731823 - 2⁴ = 138731807 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138731843) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 187615 + ... + 188352.

It is an arithmetic number, because the mean of its divisors is an integer number (17106544).

Almost surely, 2^138731823 is an apocalyptic number.

138731823 is a deficient number, since it is larger than the sum of its proper divisors (66546705).

138731823 is a wasteful number, since it uses less digits than its factorization.

138731823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 376014 (or 376011 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 138731823 is about 11778.4473934386. The cubic root of 138731823 is about 517.6767945969.

The spelling of 138731823 in words is "one hundred thirty-eight million, seven hundred thirty-one thousand, eight hundred twenty-three".