138081840 has 80 divisors (see below), whose sum is σ = 460991328. Its totient is φ = 33988608.

The previous prime is 138081833. The next prime is 138081851. The reversal of 138081840 is 48180831.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19009 + ... + 25248.

Almost surely, 2^138081840 is an apocalyptic number.

138081840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138081840 is an abundant number, since it is smaller than the sum of its proper divisors (322909488).

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

138081840 is a wasteful number, since it uses less digits than its factorization.

138081840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44286 (or 44280 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 33.

The square root of 138081840 is about 11750.8229499044. The cubic root of 138081840 is about 516.8670597385.

The spelling of 138081840 in words is "one hundred thirty-eight million, eighty-one thousand, eight hundred forty".