197909213 has 2 divisors, whose sum is σ = 197909214. Its totient is φ = 197909212.

The previous prime is 197909209. The next prime is 197909237. The reversal of 197909213 is 312909791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 169468324 + 28440889 = 13018^2 + 5333^2 .

It is an emirp because it is prime and its reverse (312909791) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 197909213 - 2² = 197909209 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (197909113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98954606 + 98954607.

It is an arithmetic number, because the mean of its divisors is an integer number (98954607).

Almost surely, 2^197909213 is an apocalyptic number.

It is an amenable number.

197909213 is a deficient number, since it is larger than the sum of its proper divisors (1).

197909213 is an equidigital number, since it uses as much as digits as its factorization.

197909213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30618, while the sum is 41.

The square root of 197909213 is about 14068.0209340191. The cubic root of 197909213 is about 582.7585722294.

The spelling of 197909213 in words is "one hundred ninety-seven million, nine hundred nine thousand, two hundred thirteen".