138655902 has 128 divisors (see below), whose sum is σ = 364953600. Its totient is φ = 34070400.

The previous prime is 138655883. The next prime is 138655991. The reversal of 138655902 is 209556831.

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 63 ways as a sum of consecutive naturals, for example, 1058377 + ... + 1058507.

It is an arithmetic number, because the mean of its divisors is an integer number (2851200).

Almost surely, 2^138655902 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138655902, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (182476800).

138655902 is an abundant number, since it is smaller than the sum of its proper divisors (226297698).

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

138655902 is a wasteful number, since it uses less digits than its factorization.

138655902 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 262.

The product of its (nonzero) digits is 64800, while the sum is 39.

The square root of 138655902 is about 11775.2240743011. The cubic root of 138655902 is about 517.5823444779.

The spelling of 138655902 in words is "one hundred thirty-eight million, six hundred fifty-five thousand, nine hundred two".