129191639 has 8 divisors (see below), whose sum is σ = 130959360. Its totient is φ = 127435896.

The previous prime is 129191633. The next prime is 129191669. The reversal of 129191639 is 936191921.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 129191639 - 2¹² = 129187543 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 129191596 and 129191605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129191633) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19892 + ... + 25574.

It is an arithmetic number, because the mean of its divisors is an integer number (16369920).

Almost surely, 2^129191639 is an apocalyptic number.

129191639 is a deficient number, since it is larger than the sum of its proper divisors (1767721).

129191639 is a wasteful number, since it uses less digits than its factorization.

129191639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5989.

The product of its digits is 26244, while the sum is 41.

The square root of 129191639 is about 11366.2499972506. The cubic root of 129191639 is about 505.5275198683.

The spelling of 129191639 in words is "one hundred twenty-nine million, one hundred ninety-one thousand, six hundred thirty-nine".