66466681 has 2 divisors, whose sum is σ = 66466682. Its totient is φ = 66466680.

The previous prime is 66466679. The next prime is 66466703. The reversal of 66466681 is 18666466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 62094400 + 4372281 = 7880^2 + 2091^2 .

It is a cyclic number.

It is not a de Polignac number, because 66466681 - 2¹ = 66466679 is a prime.

It is a super-2 number, since 2×66466681² = 8835639366311522, which contains 22 as substring.

Together with 66466679, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (66466661) 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, 33233340 + 33233341.

It is an arithmetic number, because the mean of its divisors is an integer number (33233341).

Almost surely, 2^66466681 is an apocalyptic number.

It is an amenable number.

66466681 is a deficient number, since it is larger than the sum of its proper divisors (1).

66466681 is an equidigital number, since it uses as much as digits as its factorization.

66466681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 248832, while the sum is 43.

The square root of 66466681 is about 8152.7100402259. The cubic root of 66466681 is about 405.0742758656.

The spelling of 66466681 in words is "sixty-six million, four hundred sixty-six thousand, six hundred eighty-one".