66600060691 has 2 divisors, whose sum is σ = 66600060692. Its totient is φ = 66600060690.

The previous prime is 66600060619. The next prime is 66600060713. The reversal of 66600060691 is 19606000666.

It is a happy number.

Together with previous prime (66600060619) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66600060691 - 2⁷ = 66600060563 is a prime.

It is not a weakly prime, because it can be changed into another prime (66600060091) 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, 33300030345 + 33300030346.

It is an arithmetic number, because the mean of its divisors is an integer number (33300030346).

Almost surely, 2^66600060691 is an apocalyptic number.

66600060691 is a deficient number, since it is larger than the sum of its proper divisors (1).

66600060691 is an equidigital number, since it uses as much as digits as its factorization.

66600060691 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 69984, while the sum is 40.

The spelling of 66600060691 in words is "sixty-six billion, six hundred million, sixty thousand, six hundred ninety-one".