66191 has 2 divisors, whose sum is σ = 66192. Its totient is φ = 66190.

The previous prime is 66179. The next prime is 66221. The reversal of 66191 is 19166.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66191 - 2¹⁰ = 65167 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33095 + 33096.

It is an arithmetic number, because the mean of its divisors is an integer number (33096).

2⁶⁶¹⁹¹ is an apocalyptic number.

66191 is a deficient number, since it is larger than the sum of its proper divisors (1).

66191 is an equidigital number, since it uses as much as digits as its factorization.

66191 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 324, while the sum is 23.

The square root of 66191 is about 257.2761162642. The cubic root of 66191 is about 40.4513463401.

The spelling of 66191 in words is "sixty-six thousand, one hundred ninety-one".