138857208 has 64 divisors (see below), whose sum is σ = 403488000. Its totient is φ = 38998272.

The previous prime is 138857203. The next prime is 138857333. The reversal of 138857208 is 802758831.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 138857208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138857203) by changing a digit.

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, 2908 + ... + 16916.

It is an arithmetic number, because the mean of its divisors is an integer number (6304500).

Almost surely, 2^138857208 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 138857208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (201744000).

138857208 is an abundant number, since it is smaller than the sum of its proper divisors (264630792).

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

138857208 is a wasteful number, since it uses less digits than its factorization.

138857208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14084 (or 14080 counting only the distinct ones).

The product of its (nonzero) digits is 107520, while the sum is 42.

The square root of 138857208 is about 11783.7688368365. The cubic root of 138857208 is about 517.8327053762.

The spelling of 138857208 in words is "one hundred thirty-eight million, eight hundred fifty-seven thousand, two hundred eight".