138809605 has 16 divisors (see below), whose sum is σ = 182160000. Its totient is φ = 100704960.

The previous prime is 138809591. The next prime is 138809621. The reversal of 138809605 is 506908831.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-138809605 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21271 + ... + 27019.

It is an arithmetic number, because the mean of its divisors is an integer number (11385000).

Almost surely, 2^138809605 is an apocalyptic number.

It is an amenable number.

138809605 is a deficient number, since it is larger than the sum of its proper divisors (43350395).

138809605 is a wasteful number, since it uses less digits than its factorization.

138809605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6204.

The product of its (nonzero) digits is 51840, while the sum is 40.

The square root of 138809605 is about 11781.7488090691. The cubic root of 138809605 is about 517.7735241784.

The spelling of 138809605 in words is "one hundred thirty-eight million, eight hundred nine thousand, six hundred five".