66317191 has 2 divisors, whose sum is σ = 66317192. Its totient is φ = 66317190.

The previous prime is 66317189. The next prime is 66317197. The reversal of 66317191 is 19171366.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66317191 - 2¹ = 66317189 is a prime.

Together with 66317189, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66317197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33158595 + 33158596.

It is an arithmetic number, because the mean of its divisors is an integer number (33158596).

Almost surely, 2^66317191 is an apocalyptic number.

66317191 is a deficient number, since it is larger than the sum of its proper divisors (1).

66317191 is an equidigital number, since it uses as much as digits as its factorization.

66317191 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6804, while the sum is 34.

The square root of 66317191 is about 8143.5367623656. The cubic root of 66317191 is about 404.7703641558.

The spelling of 66317191 in words is "sixty-six million, three hundred seventeen thousand, one hundred ninety-one".