138806536 has 64 divisors (see below), whose sum is σ = 295488000. Its totient is φ = 60572160.

The previous prime is 138806509. The next prime is 138806617. The reversal of 138806536 is 635608831.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 289545 + ... + 290023.

It is an arithmetic number, because the mean of its divisors is an integer number (4617000).

Almost surely, 2^138806536 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 138806536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (147744000).

138806536 is an abundant number, since it is smaller than the sum of its proper divisors (156681464).

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

138806536 is a wasteful number, since it uses less digits than its factorization.

138806536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 622 (or 618 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 40.

The square root of 138806536 is about 11781.6185645267. The cubic root of 138806536 is about 517.7697082593.

The spelling of 138806536 in words is "one hundred thirty-eight million, eight hundred six thousand, five hundred thirty-six".