666613316693 has 2 divisors, whose sum is σ = 666613316694. Its totient is φ = 666613316692.

The previous prime is 666613316659. The next prime is 666613316701. The reversal of 666613316693 is 396613316666.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 367335390724 + 299277925969 = 606082^2 + 547063^2 .

It is a cyclic number.

It is not a de Polignac number, because 666613316693 - 2⁸ = 666613316437 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666613316393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333306658346 + 333306658347.

It is an arithmetic number, because the mean of its divisors is an integer number (333306658347).

Almost surely, 2^666613316693 is an apocalyptic number.

It is an amenable number.

666613316693 is a deficient number, since it is larger than the sum of its proper divisors (1).

666613316693 is an equidigital number, since it uses as much as digits as its factorization.

666613316693 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11337408, while the sum is 56.

The spelling of 666613316693 in words is "six hundred sixty-six billion, six hundred thirteen million, three hundred sixteen thousand, six hundred ninety-three".