666323323661 has 2 divisors, whose sum is σ = 666323323662. Its totient is φ = 666323323660.

The previous prime is 666323323619. The next prime is 666323323681. The reversal of 666323323661 is 166323323666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 399953791561 + 266369532100 = 632419^2 + 516110^2 .

It is a cyclic number.

It is not a de Polignac number, because 666323323661 - 2⁶ = 666323323597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666323323681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333161661830 + 333161661831.

It is an arithmetic number, because the mean of its divisors is an integer number (333161661831).

Almost surely, 2^666323323661 is an apocalyptic number.

It is an amenable number.

666323323661 is a deficient number, since it is larger than the sum of its proper divisors (1).

666323323661 is an equidigital number, since it uses as much as digits as its factorization.

666323323661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2519424, while the sum is 47.

The spelling of 666323323661 in words is "six hundred sixty-six billion, three hundred twenty-three million, three hundred twenty-three thousand, six hundred sixty-one".