665717401 has 2 divisors, whose sum is σ = 665717402. Its totient is φ = 665717400.

The previous prime is 665717341. The next prime is 665717413. The reversal of 665717401 is 104717566.

665717401 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 659462400 + 6255001 = 25680^2 + 2501^2 .

It is a cyclic number.

It is not a de Polignac number, because 665717401 - 2²⁹ = 128846489 is a prime.

It is not a weakly prime, because it can be changed into another prime (665717491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332858700 + 332858701.

It is an arithmetic number, because the mean of its divisors is an integer number (332858701).

Almost surely, 2^665717401 is an apocalyptic number.

It is an amenable number.

665717401 is a deficient number, since it is larger than the sum of its proper divisors (1).

665717401 is an equidigital number, since it uses as much as digits as its factorization.

665717401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 35280, while the sum is 37.

The square root of 665717401 is about 25801.4999757766. The cubic root of 665717401 is about 873.1656378124.

The spelling of 665717401 in words is "six hundred sixty-five million, seven hundred seventeen thousand, four hundred one".