666198017 has 2 divisors, whose sum is σ = 666198018. Its totient is φ = 666198016.

The previous prime is 666197963. The next prime is 666198031. The reversal of 666198017 is 710891666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 441168016 + 225030001 = 21004^2 + 15001^2 .

It is a cyclic number.

It is not a de Polignac number, because 666198017 - 2⁶ = 666197953 is a prime.

It is not a weakly prime, because it can be changed into another prime (666198067) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333099008 + 333099009.

It is an arithmetic number, because the mean of its divisors is an integer number (333099009).

Almost surely, 2^666198017 is an apocalyptic number.

It is an amenable number.

666198017 is a deficient number, since it is larger than the sum of its proper divisors (1).

666198017 is an equidigital number, since it uses as much as digits as its factorization.

666198017 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108864, while the sum is 44.

The square root of 666198017 is about 25810.8120174473. The cubic root of 666198017 is about 873.3757151541.

The spelling of 666198017 in words is "six hundred sixty-six million, one hundred ninety-eight thousand, seventeen".