138208920 has 128 divisors (see below), whose sum is σ = 428544000. Its totient is φ = 35642880.

The previous prime is 138208913. The next prime is 138208969. The reversal of 138208920 is 29802831.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 578161 + ... + 578399.

It is an arithmetic number, because the mean of its divisors is an integer number (3348000).

Almost surely, 2^138208920 is an apocalyptic number.

138208920 is a gapful number since it is divisible by the number (10) 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 138208920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (214272000).

138208920 is an abundant number, since it is smaller than the sum of its proper divisors (290335080).

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

138208920 is a wasteful number, since it uses less digits than its factorization.

138208920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 393 (or 389 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 138208920 is about 11756.2289872221. The cubic root of 138208920 is about 517.0255728016.

It can be divided in two parts, 138208 and 920, that added together give a triangular number (139128 = T₅₂₇).

The spelling of 138208920 in words is "one hundred thirty-eight million, two hundred eight thousand, nine hundred twenty".