138959831 has 2 divisors, whose sum is σ = 138959832. Its totient is φ = 138959830.

The previous prime is 138959791. The next prime is 138959837.

138959831 is nontrivially palindromic in base 10.

138959831 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a palprime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138959831 is a prime.

It is a super-2 number, since 2×138959831² = 38619669263097122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138959837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69479915 + 69479916.

It is an arithmetic number, because the mean of its divisors is an integer number (69479916).

Almost surely, 2^138959831 is an apocalyptic number.

138959831 is a deficient number, since it is larger than the sum of its proper divisors (1).

138959831 is an equidigital number, since it uses as much as digits as its factorization.

138959831 is an evil number, because the sum of its binary digits is even.

The product of its digits is 233280, while the sum is 47.

The square root of 138959831 is about 11788.1224544030. The cubic root of 138959831 is about 517.9602427709.

The spelling of 138959831 in words is "one hundred thirty-eight million, nine hundred fifty-nine thousand, eight hundred thirty-one".