66189911 has 2 divisors, whose sum is σ = 66189912. Its totient is φ = 66189910.

The previous prime is 66189889. The next prime is 66189961. The reversal of 66189911 is 11998166.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66189911 - 2¹⁸ = 65927767 is a prime.

It is a super-2 number, since 2×66189911² = 8762208636375842, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66189961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33094955 + 33094956.

It is an arithmetic number, because the mean of its divisors is an integer number (33094956).

Almost surely, 2^66189911 is an apocalyptic number.

66189911 is a deficient number, since it is larger than the sum of its proper divisors (1).

66189911 is an equidigital number, since it uses as much as digits as its factorization.

66189911 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23328, while the sum is 41.

The square root of 66189911 is about 8135.7182227508. The cubic root of 66189911 is about 404.5112449846.

The spelling of 66189911 in words is "sixty-six million, one hundred eighty-nine thousand, nine hundred eleven".