138658231 has 2 divisors, whose sum is σ = 138658232. Its totient is φ = 138658230.

The previous prime is 138658211. The next prime is 138658241. The reversal of 138658231 is 132856831.

It is a strong prime.

It is an emirp because it is prime and its reverse (132856831) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 138658231 - 2¹⁷ = 138527159 is a prime.

It is a super-2 number, since 2×138658231² = 38452210048098722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138658211) 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 as a sum of consecutive naturals, namely, 69329115 + 69329116.

It is an arithmetic number, because the mean of its divisors is an integer number (69329116).

Almost surely, 2^138658231 is an apocalyptic number.

138658231 is a deficient number, since it is larger than the sum of its proper divisors (1).

138658231 is an equidigital number, since it uses as much as digits as its factorization.

138658231 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34560, while the sum is 37.

The square root of 138658231 is about 11775.3229679699. The cubic root of 138658231 is about 517.5852424013.

The spelling of 138658231 in words is "one hundred thirty-eight million, six hundred fifty-eight thousand, two hundred thirty-one".