666254417 has 2 divisors, whose sum is σ = 666254418. Its totient is φ = 666254416.

The previous prime is 666254411. The next prime is 666254461. The reversal of 666254417 is 714452666.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 481539136 + 184715281 = 21944^2 + 13591^2 .

It is a cyclic number.

It is not a de Polignac number, because 666254417 - 2⁴ = 666254401 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (666254411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333127208 + 333127209.

It is an arithmetic number, because the mean of its divisors is an integer number (333127209).

Almost surely, 2^666254417 is an apocalyptic number.

It is an amenable number.

666254417 is a deficient number, since it is larger than the sum of its proper divisors (1).

666254417 is an equidigital number, since it uses as much as digits as its factorization.

666254417 is an evil number, because the sum of its binary digits is even.

The product of its digits is 241920, while the sum is 41.

The square root of 666254417 is about 25811.9045597182. The cubic root of 666254417 is about 873.4003609796.

The spelling of 666254417 in words is "six hundred sixty-six million, two hundred fifty-four thousand, four hundred seventeen".