210191 has 2 divisors, whose sum is σ = 210192. Its totient is φ = 210190.

The previous prime is 210187. The next prime is 210193. The reversal of 210191 is 191012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 210191 - 2² = 210187 is a prime.

It is a Sophie Germain prime.

Together with 210193, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (210193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105095 + 105096.

It is an arithmetic number, because the mean of its divisors is an integer number (105096).

2²¹⁰¹⁹¹ is an apocalyptic number.

210191 is a deficient number, since it is larger than the sum of its proper divisors (1).

210191 is an equidigital number, since it uses as much as digits as its factorization.

210191 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18, while the sum is 14.

The square root of 210191 is about 458.4659202165. The cubic root of 210191 is about 59.4572345288.

It can be divided in two parts, 2101 and 91, that multiplied together give a palindrome (191191).

The spelling of 210191 in words is "two hundred ten thousand, one hundred ninety-one".