129808409 has 2 divisors, whose sum is σ = 129808410. Its totient is φ = 129808408.

The previous prime is 129808397. The next prime is 129808423. The reversal of 129808409 is 904808921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 92256025 + 37552384 = 9605^2 + 6128^2 .

It is a cyclic number.

It is not a de Polignac number, because 129808409 - 2⁸ = 129808153 is a prime.

It is a super-2 number, since 2×129808409² = 33700446094222562, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (129808429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64904204 + 64904205.

It is an arithmetic number, because the mean of its divisors is an integer number (64904205).

Almost surely, 2^129808409 is an apocalyptic number.

It is an amenable number.

129808409 is a deficient number, since it is larger than the sum of its proper divisors (1).

129808409 is an equidigital number, since it uses as much as digits as its factorization.

129808409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 41472, while the sum is 41.

The square root of 129808409 is about 11393.3493319568. The cubic root of 129808409 is about 506.3307177295.

The spelling of 129808409 in words is "one hundred twenty-nine million, eight hundred eight thousand, four hundred nine".