199912217 has 2 divisors, whose sum is σ = 199912218. Its totient is φ = 199912216.

The previous prime is 199912201. The next prime is 199912241. The reversal of 199912217 is 712219991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 173738761 + 26173456 = 13181^2 + 5116^2 .

It is a cyclic number.

It is not a de Polignac number, because 199912217 - 2⁴ = 199912201 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (199912277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99956108 + 99956109.

It is an arithmetic number, because the mean of its divisors is an integer number (99956109).

Almost surely, 2^199912217 is an apocalyptic number.

It is an amenable number.

199912217 is a deficient number, since it is larger than the sum of its proper divisors (1).

199912217 is an equidigital number, since it uses as much as digits as its factorization.

199912217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20412, while the sum is 41.

The square root of 199912217 is about 14139.0316853736. The cubic root of 199912217 is about 584.7179754387.

The spelling of 199912217 in words is "one hundred ninety-nine million, nine hundred twelve thousand, two hundred seventeen".