12909217 has 2 divisors, whose sum is σ = 12909218. Its totient is φ = 12909216.

The previous prime is 12909179. The next prime is 12909223. The reversal of 12909217 is 71290921.

12909217 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12559936 + 349281 = 3544^2 + 591^2 .

It is a cyclic number.

It is not a de Polignac number, because 12909217 - 2²³ = 4520609 is a prime.

It is not a weakly prime, because it can be changed into another prime (12909257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6454608 + 6454609.

It is an arithmetic number, because the mean of its divisors is an integer number (6454609).

Almost surely, 2^12909217 is an apocalyptic number.

It is an amenable number.

12909217 is a deficient number, since it is larger than the sum of its proper divisors (1).

12909217 is an equidigital number, since it uses as much as digits as its factorization.

12909217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2268, while the sum is 31.

The square root of 12909217 is about 3592.9398826031. The cubic root of 12909217 is about 234.5848532793.

The spelling of 12909217 in words is "twelve million, nine hundred nine thousand, two hundred seventeen".