66869191 has 2 divisors, whose sum is σ = 66869192. Its totient is φ = 66869190.

The previous prime is 66869141. The next prime is 66869207. The reversal of 66869191 is 19196866.

It is a strong prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 16169899 and 99896161.

It is a cyclic number.

It is not a de Polignac number, because 66869191 - 2⁹ = 66868679 is a 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 (66869111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33434595 + 33434596.

It is an arithmetic number, because the mean of its divisors is an integer number (33434596).

Almost surely, 2^66869191 is an apocalyptic number.

66869191 is a deficient number, since it is larger than the sum of its proper divisors (1).

66869191 is an equidigital number, since it uses as much as digits as its factorization.

66869191 is an evil number, because the sum of its binary digits is even.

The product of its digits is 139968, while the sum is 46.

The square root of 66869191 is about 8177.3584365613. The cubic root of 66869191 is about 405.8903159262.

The spelling of 66869191 in words is "sixty-six million, eight hundred sixty-nine thousand, one hundred ninety-one".