66320291 has 2 divisors, whose sum is σ = 66320292. Its totient is φ = 66320290.

The previous prime is 66320273. The next prime is 66320311. The reversal of 66320291 is 19202366.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66320291 - 2⁶ = 66320227 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (66320251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33160145 + 33160146.

It is an arithmetic number, because the mean of its divisors is an integer number (33160146).

Almost surely, 2^66320291 is an apocalyptic number.

66320291 is a deficient number, since it is larger than the sum of its proper divisors (1).

66320291 is an equidigital number, since it uses as much as digits as its factorization.

66320291 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 29.

The square root of 66320291 is about 8143.7270951328. The cubic root of 66320291 is about 404.7766710604.

The spelling of 66320291 in words is "sixty-six million, three hundred twenty thousand, two hundred ninety-one".