138843720 has 80 divisors (see below), whose sum is σ = 466680060. Its totient is φ = 37024128.

The previous prime is 138843707. The next prime is 138843751. The reversal of 138843720 is 27348831.

138843720 is nontrivially palindromic in base 16.

It can be written as a sum of positive squares in 2 ways, for example, as 125753796 + 13089924 = 11214^2 + 3618^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 18187 + ... + 24666.

Almost surely, 2^138843720 is an apocalyptic number.

138843720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138843720 is an abundant number, since it is smaller than the sum of its proper divisors (327836340).

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

138843720 is a wasteful number, since it uses less digits than its factorization.

138843720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42876 (or 42863 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 138843720 is about 11783.1965102853. The cubic root of 138843720 is about 517.8159381427.

The spelling of 138843720 in words is "one hundred thirty-eight million, eight hundred forty-three thousand, seven hundred twenty".