138231312 has 20 divisors (see below), whose sum is σ = 357097680. Its totient is φ = 46077088.

The previous prime is 138231239. The next prime is 138231319. The reversal of 138231312 is 213132831.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (138231319) 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, 1439862 + ... + 1439957.

It is an arithmetic number, because the mean of its divisors is an integer number (17854884).

Almost surely, 2^138231312 is an apocalyptic number.

138231312 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

138231312 is an abundant number, since it is smaller than the sum of its proper divisors (218866368).

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

138231312 is a wasteful number, since it uses less digits than its factorization.

138231312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2879830 (or 2879824 counting only the distinct ones).

The product of its digits is 864, while the sum is 24.

The square root of 138231312 is about 11757.1812948512. The cubic root of 138231312 is about 517.0534933619.

The spelling of 138231312 in words is "one hundred thirty-eight million, two hundred thirty-one thousand, three hundred twelve".