666644411 has 2 divisors, whose sum is σ = 666644412. Its totient is φ = 666644410.

The previous prime is 666644401. The next prime is 666644413. The reversal of 666644411 is 114446666.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 666644411 - 2¹⁸ = 666382267 is a prime.

It is a Sophie Germain prime.

Together with 666644413, it forms a pair of twin primes.

It is a Chen prime.

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is not a weakly prime, because it can be changed into another prime (666644413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333322205 + 333322206.

It is an arithmetic number, because the mean of its divisors is an integer number (333322206).

Almost surely, 2^666644411 is an apocalyptic number.

666644411 is a deficient number, since it is larger than the sum of its proper divisors (1).

666644411 is an equidigital number, since it uses as much as digits as its factorization.

666644411 is an evil number, because the sum of its binary digits is even.

The product of its digits is 82944, while the sum is 38.

The square root of 666644411 is about 25819.4579919874. The cubic root of 666644411 is about 873.5707435703.

The spelling of 666644411 in words is "six hundred sixty-six million, six hundred forty-four thousand, four hundred eleven".