129401309 has 2 divisors, whose sum is σ = 129401310. Its totient is φ = 129401308.

The previous prime is 129401303. The next prime is 129401323. The reversal of 129401309 is 903104921.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 121992025 + 7409284 = 11045^2 + 2722^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129401309 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129401303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64700654 + 64700655.

It is an arithmetic number, because the mean of its divisors is an integer number (64700655).

Almost surely, 2^129401309 is an apocalyptic number.

It is an amenable number.

129401309 is a deficient number, since it is larger than the sum of its proper divisors (1).

129401309 is an equidigital number, since it uses as much as digits as its factorization.

129401309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 29.

The square root of 129401309 is about 11375.4696166796. The cubic root of 129401309 is about 505.8008519689.

The spelling of 129401309 in words is "one hundred twenty-nine million, four hundred one thousand, three hundred nine".