217412891 has 2 divisors, whose sum is σ = 217412892. Its totient is φ = 217412890.

The previous prime is 217412887. The next prime is 217412917. The reversal of 217412891 is 198214712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 217412891 - 2² = 217412887 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (217412191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108706445 + 108706446.

It is an arithmetic number, because the mean of its divisors is an integer number (108706446).

Almost surely, 2^217412891 is an apocalyptic number.

217412891 is a deficient number, since it is larger than the sum of its proper divisors (1).

217412891 is an equidigital number, since it uses as much as digits as its factorization.

217412891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8064, while the sum is 35.

The square root of 217412891 is about 14744.9276363094. The cubic root of 217412891 is about 601.3053902748.

The spelling of 217412891 in words is "two hundred seventeen million, four hundred twelve thousand, eight hundred ninety-one".