138127939 has 4 divisors (see below), whose sum is σ = 138190624. Its totient is φ = 138065256.

The previous prime is 138127933. The next prime is 138127943. The reversal of 138127939 is 939721831.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 138127939 - 2³ = 138127931 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 138127895 and 138127904.

It is not an unprimeable number, because it can be changed into a prime (138127931) 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 in 3 ways as a sum of consecutive naturals, for example, 27912 + ... + 32485.

It is an arithmetic number, because the mean of its divisors is an integer number (34547656).

Almost surely, 2^138127939 is an apocalyptic number.

138127939 is a deficient number, since it is larger than the sum of its proper divisors (62685).

138127939 is an equidigital number, since it uses as much as digits as its factorization.

138127939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62684.

The product of its digits is 81648, while the sum is 43.

The square root of 138127939 is about 11752.7843084096. The cubic root of 138127939 is about 516.9245724993.

The spelling of 138127939 in words is "one hundred thirty-eight million, one hundred twenty-seven thousand, nine hundred thirty-nine".