138129786 has 40 divisors (see below), whose sum is σ = 311471424. Its totient is φ = 45752040.

The previous prime is 138129781. The next prime is 138129787. The reversal of 138129786 is 687921831.

It is not an unprimeable number, because it can be changed into a prime (138129781) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 23791 + ... + 29021.

Almost surely, 2^138129786 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138129786, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (155735712).

138129786 is an abundant number, since it is smaller than the sum of its proper divisors (173341638).

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

138129786 is a wasteful number, since it uses less digits than its factorization.

138129786 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5408 (or 5399 counting only the distinct ones).

The product of its digits is 145152, while the sum is 45.

The square root of 138129786 is about 11752.8628852718. The cubic root of 138129786 is about 516.9268765358.

The spelling of 138129786 in words is "one hundred thirty-eight million, one hundred twenty-nine thousand, seven hundred eighty-six".