129417209 has 4 divisors (see below), whose sum is σ = 137030004. Its totient is φ = 121804416.

The previous prime is 129417203. The next prime is 129417217. The reversal of 129417209 is 902714921.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 902714921 = 53 ⋅17032357.

It can be written as a sum of positive squares in 2 ways, for example, as 66373609 + 63043600 = 8147^2 + 7940^2 .

It is a cyclic number.

It is not a de Polignac number, because 129417209 - 2⁴ = 129417193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129417203) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3806372 + ... + 3806405.

It is an arithmetic number, because the mean of its divisors is an integer number (34257501).

Almost surely, 2^129417209 is an apocalyptic number.

It is an amenable number.

129417209 is a deficient number, since it is larger than the sum of its proper divisors (7612795).

129417209 is an equidigital number, since it uses as much as digits as its factorization.

129417209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7612794.

The product of its (nonzero) digits is 9072, while the sum is 35.

The square root of 129417209 is about 11376.1684674586. The cubic root of 129417209 is about 505.8215676382.

The spelling of 129417209 in words is "one hundred twenty-nine million, four hundred seventeen thousand, two hundred nine".