138999168 has 192 divisors, whose sum is σ = 499000320. Its totient is φ = 36080640.

The previous prime is 138999167. The next prime is 138999197. The reversal of 138999168 is 861999831.

It is a tau number, because it is divible by the number of its divisors (192).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138999167) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 87921 + ... + 89487.

It is an arithmetic number, because the mean of its divisors is an integer number (2598960).

Almost surely, 2^138999168 is an apocalyptic number.

138999168 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138999168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (249500160).

138999168 is an abundant number, since it is smaller than the sum of its proper divisors (360001152).

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

138999168 is a wasteful number, since it uses less digits than its factorization.

138999168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1605 (or 1590 counting only the distinct ones).

The product of its digits is 839808, while the sum is 54.

The square root of 138999168 is about 11789.7908378393. The cubic root of 138999168 is about 518.0091132001.

The spelling of 138999168 in words is "one hundred thirty-eight million, nine hundred ninety-nine thousand, one hundred sixty-eight".