138877231 has 2 divisors, whose sum is σ = 138877232. Its totient is φ = 138877230.

The previous prime is 138877223. The next prime is 138877237. The reversal of 138877231 is 132778831.

It is a strong prime.

It is an emirp because it is prime and its reverse (132778831) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 138877231 - 2³ = 138877223 is a prime.

It is a super-2 number, since 2×138877231² = 38573770580454722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138877237) 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, 69438615 + 69438616.

It is an arithmetic number, because the mean of its divisors is an integer number (69438616).

Almost surely, 2^138877231 is an apocalyptic number.

138877231 is a deficient number, since it is larger than the sum of its proper divisors (1).

138877231 is an equidigital number, since it uses as much as digits as its factorization.

138877231 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 56448, while the sum is 40.

The square root of 138877231 is about 11784.6184070593. The cubic root of 138877231 is about 517.8575944117.

The spelling of 138877231 in words is "one hundred thirty-eight million, eight hundred seventy-seven thousand, two hundred thirty-one".