66964081 has 2 divisors, whose sum is σ = 66964082. Its totient is φ = 66964080.

The previous prime is 66964067. The next prime is 66964087. The reversal of 66964081 is 18046966.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 36493681 + 30470400 = 6041^2 + 5520^2 .

It is a cyclic number.

It is not a de Polignac number, because 66964081 - 2⁹ = 66963569 is a prime.

It is a super-2 number, since 2×66964081² = 8968376288349122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66964087) 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, 33482040 + 33482041.

It is an arithmetic number, because the mean of its divisors is an integer number (33482041).

Almost surely, 2^66964081 is an apocalyptic number.

It is an amenable number.

66964081 is a deficient number, since it is larger than the sum of its proper divisors (1).

66964081 is an equidigital number, since it uses as much as digits as its factorization.

66964081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 62208, while the sum is 40.

The square root of 66964081 is about 8183.1583755907. The cubic root of 66964081 is about 406.0822165997.

The spelling of 66964081 in words is "sixty-six million, nine hundred sixty-four thousand, eighty-one".