129201217 has 2 divisors, whose sum is σ = 129201218. Its totient is φ = 129201216.

The previous prime is 129201179. The next prime is 129201251. The reversal of 129201217 is 712102921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 104837121 + 24364096 = 10239^2 + 4936^2 .

It is an emirp because it is prime and its reverse (712102921) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 129201217 - 2⁷ = 129201089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 129201191 and 129201200.

It is not a weakly prime, because it can be changed into another prime (129201287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64600608 + 64600609.

It is an arithmetic number, because the mean of its divisors is an integer number (64600609).

Almost surely, 2^129201217 is an apocalyptic number.

It is an amenable number.

129201217 is a deficient number, since it is larger than the sum of its proper divisors (1).

129201217 is an equidigital number, since it uses as much as digits as its factorization.

129201217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 504, while the sum is 25.

The square root of 129201217 is about 11366.6713245347. The cubic root of 129201217 is about 505.5400124800.

The spelling of 129201217 in words is "one hundred twenty-nine million, two hundred one thousand, two hundred seventeen".