129898809 has 24 divisors (see below), whose sum is σ = 195205920. Its totient is φ = 86321376.

The previous prime is 129898789. The next prime is 129898841. The reversal of 129898809 is 908898921.

It is a happy number.

It is not a de Polignac number, because 129898809 - 2⁵ = 129898777 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (129898889) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 98734 + ... + 100040.

It is an arithmetic number, because the mean of its divisors is an integer number (8133580).

Almost surely, 2^129898809 is an apocalyptic number.

It is an amenable number.

129898809 is a deficient number, since it is larger than the sum of its proper divisors (65307111).

129898809 is an equidigital number, since it uses as much as digits as its factorization.

129898809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1731 (or 1719 counting only the distinct ones).

The product of its (nonzero) digits is 746496, while the sum is 54.

The square root of 129898809 is about 11397.3158682209. The cubic root of 129898809 is about 506.4482285438.

The spelling of 129898809 in words is "one hundred twenty-nine million, eight hundred ninety-eight thousand, eight hundred nine".