138279390 has 16 divisors (see below), whose sum is σ = 331870608. Its totient is φ = 36874496.

The previous prime is 138279367. The next prime is 138279391. The reversal of 138279390 is 93972831.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138279391) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2304627 + ... + 2304686.

It is an arithmetic number, because the mean of its divisors is an integer number (20741913).

Almost surely, 2^138279390 is an apocalyptic number.

138279390 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

138279390 is an abundant number, since it is smaller than the sum of its proper divisors (193591218).

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

138279390 is a wasteful number, since it uses less digits than its factorization.

138279390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4609323.

The product of its (nonzero) digits is 81648, while the sum is 42.

The square root of 138279390 is about 11759.2257398181. The cubic root of 138279390 is about 517.1134315819.

The spelling of 138279390 in words is "one hundred thirty-eight million, two hundred seventy-nine thousand, three hundred ninety".