138406872 has 32 divisors (see below), whose sum is σ = 346967280. Its totient is φ = 46008960.

The previous prime is 138406859. The next prime is 138406897. The reversal of 138406872 is 278604831.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 138406872.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1222 + ... + 16682.

Almost surely, 2^138406872 is an apocalyptic number.

138406872 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

138406872 is an abundant number, since it is smaller than the sum of its proper divisors (208560408).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

138406872 is a wasteful number, since it uses less digits than its factorization.

138406872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15843 (or 15839 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 39.

The square root of 138406872 is about 11764.6450010189. The cubic root of 138406872 is about 517.2722945102.

The spelling of 138406872 in words is "one hundred thirty-eight million, four hundred six thousand, eight hundred seventy-two".