138442231 has 2 divisors, whose sum is σ = 138442232. Its totient is φ = 138442230.

The previous prime is 138442217. The next prime is 138442253. The reversal of 138442231 is 132244831.

138442231 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 138442231 - 2⁷ = 138442103 is a prime.

It is a super-2 number, since 2×138442231² = 38332502648514722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 138442231.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138442631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69221115 + 69221116.

It is an arithmetic number, because the mean of its divisors is an integer number (69221116).

Almost surely, 2^138442231 is an apocalyptic number.

138442231 is a deficient number, since it is larger than the sum of its proper divisors (1).

138442231 is an equidigital number, since it uses as much as digits as its factorization.

138442231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4608, while the sum is 28.

The square root of 138442231 is about 11766.1476703295. The cubic root of 138442231 is about 517.3163401886.

The spelling of 138442231 in words is "one hundred thirty-eight million, four hundred forty-two thousand, two hundred thirty-one".