138933381 has 16 divisors (see below), whose sum is σ = 188296256. Its totient is φ = 91103616.

The previous prime is 138933371. The next prime is 138933383. The reversal of 138933381 is 183339831.

It is not a de Polignac number, because 138933381 - 2⁵ = 138933349 is a prime.

It is a super-2 number, since 2×138933381² = 38604968712182322, 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 (138933383) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 113931 + ... + 115143.

It is an arithmetic number, because the mean of its divisors is an integer number (11768516).

Almost surely, 2^138933381 is an apocalyptic number.

It is an amenable number.

138933381 is a deficient number, since it is larger than the sum of its proper divisors (49362875).

138933381 is a wasteful number, since it uses less digits than its factorization.

138933381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1812.

The product of its digits is 46656, while the sum is 39.

The square root of 138933381 is about 11787.0005090354. Note that the first 3 decimals coincide. The cubic root of 138933381 is about 517.9273773554.

The spelling of 138933381 in words is "one hundred thirty-eight million, nine hundred thirty-three thousand, three hundred eighty-one".