199972217 has 2 divisors, whose sum is σ = 199972218. Its totient is φ = 199972216.

The previous prime is 199972151. The next prime is 199972237. The reversal of 199972217 is 712279991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 168376576 + 31595641 = 12976^2 + 5621^2 .

It is a cyclic number.

It is not a de Polignac number, because 199972217 - 2¹⁰ = 199971193 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (199972237) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99986108 + 99986109.

It is an arithmetic number, because the mean of its divisors is an integer number (99986109).

Almost surely, 2^199972217 is an apocalyptic number.

It is an amenable number.

199972217 is a deficient number, since it is larger than the sum of its proper divisors (1).

199972217 is an equidigital number, since it uses as much as digits as its factorization.

199972217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 142884, while the sum is 47.

The square root of 199972217 is about 14141.1533122302. The cubic root of 199972217 is about 584.7764670603.

The spelling of 199972217 in words is "one hundred ninety-nine million, nine hundred seventy-two thousand, two hundred seventeen".