129392217 has 6 divisors (see below), whose sum is σ = 186899882. Its totient is φ = 86261472.

The previous prime is 129392213. The next prime is 129392231. The reversal of 129392217 is 712293921.

It can be written as a sum of positive squares in only one way, i.e., 127712601 + 1679616 = 11301^2 + 1296^2 .

It is not a de Polignac number, because 129392217 - 2² = 129392213 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129392213) 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 in 5 ways as a sum of consecutive naturals, for example, 7188448 + ... + 7188465.

Almost surely, 2^129392217 is an apocalyptic number.

It is an amenable number.

129392217 is a deficient number, since it is larger than the sum of its proper divisors (57507665).

129392217 is a wasteful number, since it uses less digits than its factorization.

129392217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14376919 (or 14376916 counting only the distinct ones).

The product of its digits is 13608, while the sum is 36.

The square root of 129392217 is about 11375.0699778067. The cubic root of 129392217 is about 505.7890054915.

The spelling of 129392217 in words is "one hundred twenty-nine million, three hundred ninety-two thousand, two hundred seventeen".