66164591 has 2 divisors, whose sum is σ = 66164592. Its totient is φ = 66164590.

The previous prime is 66164569. The next prime is 66164641. The reversal of 66164591 is 19546166.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66164591 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66164531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33082295 + 33082296.

It is an arithmetic number, because the mean of its divisors is an integer number (33082296).

Almost surely, 2^66164591 is an apocalyptic number.

66164591 is a deficient number, since it is larger than the sum of its proper divisors (1).

66164591 is an equidigital number, since it uses as much as digits as its factorization.

66164591 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38880, while the sum is 38.

The square root of 66164591 is about 8134.1619728156. The cubic root of 66164591 is about 404.4596584167.

The spelling of 66164591 in words is "sixty-six million, one hundred sixty-four thousand, five hundred ninety-one".