66339281 has 2 divisors, whose sum is σ = 66339282. Its totient is φ = 66339280.

The previous prime is 66339233. The next prime is 66339289. The reversal of 66339281 is 18293366.

66339281 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 55056400 + 11282881 = 7420^2 + 3359^2 .

It is a cyclic number.

It is not a de Polignac number, because 66339281 - 2¹⁴ = 66322897 is a prime.

It is a super-2 number, since 2×66339281² = 8801800407193922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66339289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33169640 + 33169641.

It is an arithmetic number, because the mean of its divisors is an integer number (33169641).

Almost surely, 2^66339281 is an apocalyptic number.

It is an amenable number.

66339281 is a deficient number, since it is larger than the sum of its proper divisors (1).

66339281 is an equidigital number, since it uses as much as digits as its factorization.

66339281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 46656, while the sum is 38.

The square root of 66339281 is about 8144.8929397507. The cubic root of 66339281 is about 404.8153016480.

The spelling of 66339281 in words is "sixty-six million, three hundred thirty-nine thousand, two hundred eighty-one".