138426639 has 8 divisors (see below), whose sum is σ = 198766512. Its totient is φ = 85185600.

The previous prime is 138426577. The next prime is 138426667. The reversal of 138426639 is 936624831.

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

It is not a de Polignac number, because 138426639 - 2⁷ = 138426511 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 138426639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138426679) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1774662 + ... + 1774739.

It is an arithmetic number, because the mean of its divisors is an integer number (24845814).

Almost surely, 2^138426639 is an apocalyptic number.

138426639 is a deficient number, since it is larger than the sum of its proper divisors (60339873).

138426639 is a wasteful number, since it uses less digits than its factorization.

138426639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3549417.

The product of its digits is 186624, while the sum is 42.

The square root of 138426639 is about 11765.4850728731. The cubic root of 138426639 is about 517.2969186120.

The spelling of 138426639 in words is "one hundred thirty-eight million, four hundred twenty-six thousand, six hundred thirty-nine".