666604013 has 2 divisors, whose sum is σ = 666604014. Its totient is φ = 666604012.

The previous prime is 666603991. The next prime is 666604021. The reversal of 666604013 is 310406666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 560884489 + 105719524 = 23683^2 + 10282^2 .

It is a cyclic number.

It is not a de Polignac number, because 666604013 - 2¹² = 666599917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666604093) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333302006 + 333302007.

It is an arithmetic number, because the mean of its divisors is an integer number (333302007).

Almost surely, 2^666604013 is an apocalyptic number.

It is an amenable number.

666604013 is a deficient number, since it is larger than the sum of its proper divisors (1).

666604013 is an equidigital number, since it uses as much as digits as its factorization.

666604013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 32.

The square root of 666604013 is about 25818.6756631706. The cubic root of 666604013 is about 873.5530973693.

The spelling of 666604013 in words is "six hundred sixty-six million, six hundred four thousand, thirteen".