129636217 has 2 divisors, whose sum is σ = 129636218. Its totient is φ = 129636216.

The previous prime is 129636209. The next prime is 129636253. The reversal of 129636217 is 712636921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 82246761 + 47389456 = 9069^2 + 6884^2 .

It is a cyclic number.

It is not a de Polignac number, because 129636217 - 2³ = 129636209 is a prime.

It is not a weakly prime, because it can be changed into another prime (129636817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64818108 + 64818109.

It is an arithmetic number, because the mean of its divisors is an integer number (64818109).

Almost surely, 2^129636217 is an apocalyptic number.

It is an amenable number.

129636217 is a deficient number, since it is larger than the sum of its proper divisors (1).

129636217 is an equidigital number, since it uses as much as digits as its factorization.

129636217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27216, while the sum is 37.

The square root of 129636217 is about 11385.7901350763. The cubic root of 129636217 is about 506.1067346067.

The spelling of 129636217 in words is "one hundred twenty-nine million, six hundred thirty-six thousand, two hundred seventeen".