217209241 has 2 divisors, whose sum is σ = 217209242. Its totient is φ = 217209240.

The previous prime is 217209233. The next prime is 217209247. The reversal of 217209241 is 142902712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 172265625 + 44943616 = 13125^2 + 6704^2 .

It is a cyclic number.

It is not a de Polignac number, because 217209241 - 2³ = 217209233 is a prime.

It is not a weakly prime, because it can be changed into another prime (217209247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108604620 + 108604621.

It is an arithmetic number, because the mean of its divisors is an integer number (108604621).

Almost surely, 2^217209241 is an apocalyptic number.

It is an amenable number.

217209241 is a deficient number, since it is larger than the sum of its proper divisors (1).

217209241 is an equidigital number, since it uses as much as digits as its factorization.

217209241 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 217209241 is about 14738.0202537519. The cubic root of 217209241 is about 601.1175846411.

The spelling of 217209241 in words is "two hundred seventeen million, two hundred nine thousand, two hundred forty-one".