138233279 has 4 divisors (see below), whose sum is σ = 138258360. Its totient is φ = 138208200.

The previous prime is 138233267. The next prime is 138233299. The reversal of 138233279 is 972332831.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 972332831 = 1741 ⋅558491.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138233279 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138233209) 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, 272 + ... + 16629.

It is an arithmetic number, because the mean of its divisors is an integer number (34564590).

Almost surely, 2^138233279 is an apocalyptic number.

138233279 is a deficient number, since it is larger than the sum of its proper divisors (25081).

138233279 is an equidigital number, since it uses as much as digits as its factorization.

138233279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25080.

The product of its digits is 54432, while the sum is 38.

The square root of 138233279 is about 11757.2649455560. The cubic root of 138233279 is about 517.0559458679.

The spelling of 138233279 in words is "one hundred thirty-eight million, two hundred thirty-three thousand, two hundred seventy-nine".