66330191 has 2 divisors, whose sum is σ = 66330192. Its totient is φ = 66330190.

The previous prime is 66330179. The next prime is 66330193. The reversal of 66330191 is 19103366.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66330191 - 2¹⁰ = 66329167 is a prime.

It is a Sophie Germain prime.

Together with 66330193, 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 (66330193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33165095 + 33165096.

It is an arithmetic number, because the mean of its divisors is an integer number (33165096).

Almost surely, 2^66330191 is an apocalyptic number.

66330191 is a deficient number, since it is larger than the sum of its proper divisors (1).

66330191 is an equidigital number, since it uses as much as digits as its factorization.

66330191 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2916, while the sum is 29.

The square root of 66330191 is about 8144.3349022495. The cubic root of 66330191 is about 404.7968111492.

The spelling of 66330191 in words is "sixty-six million, three hundred thirty thousand, one hundred ninety-one".