138599431 has 2 divisors, whose sum is σ = 138599432. Its totient is φ = 138599430.

The previous prime is 138599429. The next prime is 138599467. The reversal of 138599431 is 134995831.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 138599431 - 2¹ = 138599429 is a prime.

It is a super-2 number, since 2×138599431² = 38419604547047522, which contains 22 as substring.

Together with 138599429, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138599831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69299715 + 69299716.

It is an arithmetic number, because the mean of its divisors is an integer number (69299716).

Almost surely, 2^138599431 is an apocalyptic number.

138599431 is a deficient number, since it is larger than the sum of its proper divisors (1).

138599431 is an equidigital number, since it uses as much as digits as its factorization.

138599431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 116640, while the sum is 43.

The square root of 138599431 is about 11772.8259564134. The cubic root of 138599431 is about 517.5120689228.

The spelling of 138599431 in words is "one hundred thirty-eight million, five hundred ninety-nine thousand, four hundred thirty-one".