6660191 has 2 divisors, whose sum is σ = 6660192. Its totient is φ = 6660190.

The previous prime is 6660161. The next prime is 6660193. The reversal of 6660191 is 1910666.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6660191 - 2¹⁴ = 6643807 is a prime.

Together with 6660193, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p₄₅₄₉₆₁ and since 6660191 and 454961 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6660193) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3330095 + 3330096.

It is an arithmetic number, because the mean of its divisors is an integer number (3330096).

Almost surely, 2^6660191 is an apocalyptic number.

6660191 is a deficient number, since it is larger than the sum of its proper divisors (1).

6660191 is an equidigital number, since it uses as much as digits as its factorization.

6660191 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 29.

The square root of 6660191 is about 2580.7345853458. The cubic root of 6660191 is about 188.1462476783.

The spelling of 6660191 in words is "six million, six hundred sixty thousand, one hundred ninety-one".