665617417 has 2 divisors, whose sum is σ = 665617418. Its totient is φ = 665617416.

The previous prime is 665617397. The next prime is 665617429. The reversal of 665617417 is 714716566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 433847241 + 231770176 = 20829^2 + 15224^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665617417 is a prime.

It is not a weakly prime, because it can be changed into another prime (665617487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332808708 + 332808709.

It is an arithmetic number, because the mean of its divisors is an integer number (332808709).

Almost surely, 2^665617417 is an apocalyptic number.

It is an amenable number.

665617417 is a deficient number, since it is larger than the sum of its proper divisors (1).

665617417 is an equidigital number, since it uses as much as digits as its factorization.

665617417 is an evil number, because the sum of its binary digits is even.

The product of its digits is 211680, while the sum is 43.

The square root of 665617417 is about 25799.5623412491. The cubic root of 665617417 is about 873.1219220835.

The spelling of 665617417 in words is "six hundred sixty-five million, six hundred seventeen thousand, four hundred seventeen".