138659620 has 48 divisors (see below), whose sum is σ = 318846528. Its totient is φ = 50232960.

The previous prime is 138659611. The next prime is 138659681. The reversal of 138659620 is 26956831.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 66514 + ... + 68566.

It is an arithmetic number, because the mean of its divisors is an integer number (6642636).

Almost surely, 2^138659620 is an apocalyptic number.

138659620 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 138659620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (159423264).

138659620 is an abundant number, since it is smaller than the sum of its proper divisors (180186908).

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

138659620 is a wasteful number, since it uses less digits than its factorization.

138659620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2380 (or 2378 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 40.

The square root of 138659620 is about 11775.3819470962. The cubic root of 138659620 is about 517.5869706879.

The spelling of 138659620 in words is "one hundred thirty-eight million, six hundred fifty-nine thousand, six hundred twenty".