66365791 has 2 divisors, whose sum is σ = 66365792. Its totient is φ = 66365790.

The previous prime is 66365777. The next prime is 66365809. The reversal of 66365791 is 19756366.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66365791 - 2¹⁷ = 66234719 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66365771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33182895 + 33182896.

It is an arithmetic number, because the mean of its divisors is an integer number (33182896).

Almost surely, 2^66365791 is an apocalyptic number.

66365791 is a deficient number, since it is larger than the sum of its proper divisors (1).

66365791 is an equidigital number, since it uses as much as digits as its factorization.

66365791 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 204120, while the sum is 43.

The square root of 66365791 is about 8146.5201773518. The cubic root of 66365791 is about 404.8692175396.

The spelling of 66365791 in words is "sixty-six million, three hundred sixty-five thousand, seven hundred ninety-one".