66681011 has 2 divisors, whose sum is σ = 66681012. Its totient is φ = 66681010.

The previous prime is 66681007. The next prime is 66681037. The reversal of 66681011 is 11018666.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66681011 - 2² = 66681007 is a prime.

It is not a weakly prime, because it can be changed into another prime (66681061) 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, 33340505 + 33340506.

It is an arithmetic number, because the mean of its divisors is an integer number (33340506).

Almost surely, 2^66681011 is an apocalyptic number.

66681011 is a deficient number, since it is larger than the sum of its proper divisors (1).

66681011 is an equidigital number, since it uses as much as digits as its factorization.

66681011 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 66681011 is about 8165.8441694659. The cubic root of 66681011 is about 405.5092126636.

Adding to 66681011 its reverse (11018666), we get a palindrome (77699677).

The spelling of 66681011 in words is "sixty-six million, six hundred eighty-one thousand, eleven".