138733231 has 16 divisors (see below), whose sum is σ = 179737600. Its totient is φ = 103988448.

The previous prime is 138733223. The next prime is 138733267. The reversal of 138733231 is 132337831.

138733231 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 138733231 - 2³ = 138733223 is a prime.

It is a super-2 number, since 2×138733231² = 38493818767398722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 138733193 and 138733202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138733201) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38391 + ... + 41848.

It is an arithmetic number, because the mean of its divisors is an integer number (11233600).

Almost surely, 2^138733231 is an apocalyptic number.

138733231 is a deficient number, since it is larger than the sum of its proper divisors (41004369).

138733231 is a wasteful number, since it uses less digits than its factorization.

138733231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80278.

The product of its digits is 9072, while the sum is 31.

The square root of 138733231 is about 11778.5071634736. The cubic root of 138733231 is about 517.6785459049.

The spelling of 138733231 in words is "one hundred thirty-eight million, seven hundred thirty-three thousand, two hundred thirty-one".