138886668 has 72 divisors (see below), whose sum is σ = 373726080. Its totient is φ = 43338240.

The previous prime is 138886621. The next prime is 138886669. The reversal of 138886668 is 866688831.

It is not an unprimeable number, because it can be changed into a prime (138886669) 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, 139653 + ... + 140643.

It is an arithmetic number, because the mean of its divisors is an integer number (5190640).

Almost surely, 2^138886668 is an apocalyptic number.

138886668 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 138886668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (186863040).

138886668 is an abundant number, since it is smaller than the sum of its proper divisors (234839412).

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

138886668 is a wasteful number, since it uses less digits than its factorization.

138886668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1247 (or 1242 counting only the distinct ones).

The product of its digits is 2654208, while the sum is 54.

The square root of 138886668 is about 11785.0187950635. The cubic root of 138886668 is about 517.8693239837.

The spelling of 138886668 in words is "one hundred thirty-eight million, eight hundred eighty-six thousand, six hundred sixty-eight".