666001313 has 2 divisors, whose sum is σ = 666001314. Its totient is φ = 666001312.

The previous prime is 666001307. The next prime is 666001361. The reversal of 666001313 is 313100666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 666001249 + 64 = 25807^2 + 8^2 .

It is a cyclic number.

It is not a de Polignac number, because 666001313 - 2⁸ = 666001057 is a prime.

It is not a weakly prime, because it can be changed into another prime (666001393) 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, 333000656 + 333000657.

It is an arithmetic number, because the mean of its divisors is an integer number (333000657).

Almost surely, 2^666001313 is an apocalyptic number.

It is an amenable number.

666001313 is a deficient number, since it is larger than the sum of its proper divisors (1).

666001313 is an equidigital number, since it uses as much as digits as its factorization.

666001313 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1944, while the sum is 26.

The square root of 666001313 is about 25807.0012399736. The cubic root of 666001313 is about 873.2897480175.

Adding to 666001313 its reverse (313100666), we get a palindrome (979101979).

The spelling of 666001313 in words is "six hundred sixty-six million, one thousand, three hundred thirteen".