138986840 has 32 divisors (see below), whose sum is σ = 314653680. Its totient is φ = 55251072.

The previous prime is 138986839. The next prime is 138986851. The reversal of 138986840 is 48689831.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4139 + ... + 17178.

Almost surely, 2^138986840 is an apocalyptic number.

138986840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138986840 is an abundant number, since it is smaller than the sum of its proper divisors (175666840).

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

138986840 is a wasteful number, since it uses less digits than its factorization.

138986840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21491 (or 21487 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 47.

The square root of 138986840 is about 11789.2680010253. The cubic root of 138986840 is about 517.9937984678.

The spelling of 138986840 in words is "one hundred thirty-eight million, nine hundred eighty-six thousand, eight hundred forty".