129823209 has 8 divisors (see below), whose sum is σ = 192330720. Its totient is φ = 86548788.

The previous prime is 129823193. The next prime is 129823217. The reversal of 129823209 is 902328921.

It is not a de Polignac number, because 129823209 - 2⁴ = 129823193 is a prime.

It is not an unprimeable number, because it can be changed into a prime (129824209) 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, 2404107 + ... + 2404160.

It is an arithmetic number, because the mean of its divisors is an integer number (24041340).

Almost surely, 2^129823209 is an apocalyptic number.

It is an amenable number.

129823209 is a deficient number, since it is larger than the sum of its proper divisors (62507511).

129823209 is an equidigital number, since it uses as much as digits as its factorization.

129823209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4808276 (or 4808270 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 129823209 is about 11393.9988151658. The cubic root of 129823209 is about 506.3499599596.

The spelling of 129823209 in words is "one hundred twenty-nine million, eight hundred twenty-three thousand, two hundred nine".