138957639 has 8 divisors (see below), whose sum is σ = 189585792. Its totient is φ = 90483960.

The previous prime is 138957629. The next prime is 138957649. The reversal of 138957639 is 936759831.

It is an interprime number because it is at equal distance from previous prime (138957629) and next prime (138957649).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 138957639 - 2²⁰ = 137909063 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 138957591 and 138957600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138957629) 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 in 7 ways as a sum of consecutive naturals, for example, 538467 + ... + 538724.

It is an arithmetic number, because the mean of its divisors is an integer number (23698224).

Almost surely, 2^138957639 is an apocalyptic number.

138957639 is a deficient number, since it is larger than the sum of its proper divisors (50628153).

138957639 is a wasteful number, since it uses less digits than its factorization.

138957639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1077237.

The product of its digits is 1224720, while the sum is 51.

The square root of 138957639 is about 11788.0294790945. The cubic root of 138957639 is about 517.9575192624.

The spelling of 138957639 in words is "one hundred thirty-eight million, nine hundred fifty-seven thousand, six hundred thirty-nine".