666666241 has 2 divisors, whose sum is σ = 666666242. Its totient is φ = 666666240.

The previous prime is 666666229. The next prime is 666666263. The reversal of 666666241 is 142666666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 547747216 + 118919025 = 23404^2 + 10905^2 .

It is a cyclic number.

It is not a de Polignac number, because 666666241 - 2⁷ = 666666113 is a prime.

It is not a weakly prime, because it can be changed into another prime (666666211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333333120 + 333333121.

It is an arithmetic number, because the mean of its divisors is an integer number (333333121).

Almost surely, 2^666666241 is an apocalyptic number.

It is an amenable number.

666666241 is a deficient number, since it is larger than the sum of its proper divisors (1).

666666241 is an equidigital number, since it uses as much as digits as its factorization.

666666241 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 373248, while the sum is 43.

The square root of 666666241 is about 25819.8807317152. The cubic root of 666666241 is about 873.5802788092.

The spelling of 666666241 in words is "six hundred sixty-six million, six hundred sixty-six thousand, two hundred forty-one".