138359808 has 66 divisors (see below), whose sum is σ = 399537554. Its totient is φ = 46116864.

The previous prime is 138359807. The next prime is 138359813. The reversal of 138359808 is 808953831.

It can be written as a sum of positive squares in only one way, i.e., 128323584 + 10036224 = 11328^2 + 3168^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138359803) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1710 + ... + 16722.

Almost surely, 2^138359808 is an apocalyptic number.

138359808 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 138359808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (199768777).

138359808 is an abundant number, since it is smaller than the sum of its proper divisors (261177746).

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

138359808 is a wasteful number, since it uses less digits than its factorization.

138359808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15039 (or 15018 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 45.

The square root of 138359808 is about 11762.6446005990. The cubic root of 138359808 is about 517.2136566144.

The spelling of 138359808 in words is "one hundred thirty-eight million, three hundred fifty-nine thousand, eight hundred eight".