138136391226 has 80 divisors (see below), whose sum is σ = 312017013000. Its totient is φ = 45676006272.

The previous prime is 138136391213. The next prime is 138136391269. The reversal of 138136391226 is 622193631831.

138136391226 is a `hidden beast` number, since 1 + 3 + 8 + 1 + 3 + 639 + 1 + 2 + 2 + 6 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 67114674225 + 71021717001 = 259065^2 + 266499^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 20586360 + ... + 20593068.

Almost surely, 2^138136391226 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138136391226, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (156008506500).

138136391226 is an abundant number, since it is smaller than the sum of its proper divisors (173880621774).

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

138136391226 is a wasteful number, since it uses less digits than its factorization.

138136391226 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7725 (or 7716 counting only the distinct ones).

The product of its digits is 279936, while the sum is 45.

The spelling of 138136391226 in words is "one hundred thirty-eight billion, one hundred thirty-six million, three hundred ninety-one thousand, two hundred twenty-six".