211938191 has 2 divisors, whose sum is σ = 211938192. Its totient is φ = 211938190.

The previous prime is 211938187. The next prime is 211938193. The reversal of 211938191 is 191839112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 211938191 - 2² = 211938187 is a prime.

Together with 211938193, 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 (211938193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105969095 + 105969096.

It is an arithmetic number, because the mean of its divisors is an integer number (105969096).

Almost surely, 2^211938191 is an apocalyptic number.

211938191 is a deficient number, since it is larger than the sum of its proper divisors (1).

211938191 is an equidigital number, since it uses as much as digits as its factorization.

211938191 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3888, while the sum is 35.

The square root of 211938191 is about 14558.0970940573. The cubic root of 211938191 is about 596.2152419501.

The spelling of 211938191 in words is "two hundred eleven million, nine hundred thirty-eight thousand, one hundred ninety-one".