138992168 has 64 divisors (see below), whose sum is σ = 307359360. Its totient is φ = 57689856.

The previous prime is 138992167. The next prime is 138992209. The reversal of 138992168 is 861299831.

It is a hoax number, since the sum of its digits (47) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (138992167) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 474230 + ... + 474522.

It is an arithmetic number, because the mean of its divisors is an integer number (4802490).

Almost surely, 2^138992168 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138992168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (153679680).

138992168 is an abundant number, since it is smaller than the sum of its proper divisors (168367192).

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

138992168 is a wasteful number, since it uses less digits than its factorization.

138992168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 546 (or 542 counting only the distinct ones).

The product of its digits is 186624, while the sum is 47.

The square root of 138992168 is about 11789.4939670878. The cubic root of 138992168 is about 518.0004174055. Note that the first 3 decimals are identical.

The spelling of 138992168 in words is "one hundred thirty-eight million, nine hundred ninety-two thousand, one hundred sixty-eight".