138990168 has 192 divisors, whose sum is σ = 424569600. Its totient is φ = 42456960.

The previous prime is 138990161. The next prime is 138990191. The reversal of 138990168 is 861099831.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138990161) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1957573 + ... + 1957643.

It is an arithmetic number, because the mean of its divisors is an integer number (2211300).

Almost surely, 2^138990168 is an apocalyptic number.

138990168 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 138990168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (212284800).

138990168 is an abundant number, since it is smaller than the sum of its proper divisors (285579432).

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

138990168 is a wasteful number, since it uses less digits than its factorization.

138990168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164 (or 148 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The square root of 138990168 is about 11789.4091455000. The cubic root of 138990168 is about 517.9979328391.

The spelling of 138990168 in words is "one hundred thirty-eight million, nine hundred ninety thousand, one hundred sixty-eight".