138243933 has 6 divisors (see below), whose sum is σ = 199685694. Its totient is φ = 92162616.

The previous prime is 138243913. The next prime is 138243947. The reversal of 138243933 is 339342831.

It can be written as a sum of positive squares in only one way, i.e., 137663289 + 580644 = 11733^2 + 762^2 .

It is not a de Polignac number, because 138243933 - 2⁵ = 138243901 is a prime.

It is a super-2 number, since 2×138243933² = 38222770022616978, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138243913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7680210 + ... + 7680227.

It is an arithmetic number, because the mean of its divisors is an integer number (33280949).

Almost surely, 2^138243933 is an apocalyptic number.

It is an amenable number.

138243933 is a deficient number, since it is larger than the sum of its proper divisors (61441761).

138243933 is a wasteful number, since it uses less digits than its factorization.

138243933 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15360443 (or 15360440 counting only the distinct ones).

The product of its digits is 46656, while the sum is 36.

The square root of 138243933 is about 11757.7180183912. The cubic root of 138243933 is about 517.0692291443.

The spelling of 138243933 in words is "one hundred thirty-eight million, two hundred forty-three thousand, nine hundred thirty-three".