129231639 has 16 divisors (see below), whose sum is σ = 196630240. Its totient is φ = 83825280.

The previous prime is 129231607. The next prime is 129231701. The reversal of 129231639 is 936132921.

It is a happy number.

129231639 is a `hidden beast` number, since 12 + 9 + 2 + 3 + 1 + 639 = 666.

It is not a de Polignac number, because 129231639 - 2⁵ = 129231607 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129231239) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 63682 + ... + 65679.

It is an arithmetic number, because the mean of its divisors is an integer number (12289390).

Almost surely, 2^129231639 is an apocalyptic number.

129231639 is a deficient number, since it is larger than the sum of its proper divisors (67398601).

129231639 is a wasteful number, since it uses less digits than its factorization.

129231639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129407 (or 129401 counting only the distinct ones).

The product of its digits is 17496, while the sum is 36.

The square root of 129231639 is about 11368.0094563648. The cubic root of 129231639 is about 505.5796878836.

The spelling of 129231639 in words is "one hundred twenty-nine million, two hundred thirty-one thousand, six hundred thirty-nine".