129891309 has 8 divisors (see below), whose sum is σ = 175561152. Its totient is φ = 85407840.

The previous prime is 129891301. The next prime is 129891329. The reversal of 129891309 is 903198921.

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

It is not a de Polignac number, because 129891309 - 2³ = 129891301 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129891301) 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, 296337 + ... + 296774.

It is an arithmetic number, because the mean of its divisors is an integer number (21945144).

Almost surely, 2^129891309 is an apocalyptic number.

It is an amenable number.

129891309 is a deficient number, since it is larger than the sum of its proper divisors (45669843).

129891309 is an equidigital number, since it uses as much as digits as its factorization.

129891309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 593187.

The product of its (nonzero) digits is 34992, while the sum is 42.

The square root of 129891309 is about 11396.9868386341. The cubic root of 129891309 is about 506.4384813803.

The spelling of 129891309 in words is "one hundred twenty-nine million, eight hundred ninety-one thousand, three hundred nine".