138445591 has 2 divisors, whose sum is σ = 138445592. Its totient is φ = 138445590.

The previous prime is 138445553. The next prime is 138445627. The reversal of 138445591 is 195544831.

It is a strong prime.

It is an emirp because it is prime and its reverse (195544831) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 138445591 - 2²⁵ = 104891159 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138445511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69222795 + 69222796.

It is an arithmetic number, because the mean of its divisors is an integer number (69222796).

Almost surely, 2^138445591 is an apocalyptic number.

138445591 is a deficient number, since it is larger than the sum of its proper divisors (1).

138445591 is an equidigital number, since it uses as much as digits as its factorization.

138445591 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 86400, while the sum is 40.

The square root of 138445591 is about 11766.2904519649. The cubic root of 138445591 is about 517.3205252528.

The spelling of 138445591 in words is "one hundred thirty-eight million, four hundred forty-five thousand, five hundred ninety-one".