664247197 has 2 divisors, whose sum is σ = 664247198. Its totient is φ = 664247196.

The previous prime is 664247183. The next prime is 664247209. The reversal of 664247197 is 791742466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 654643396 + 9603801 = 25586^2 + 3099^2 .

It is a cyclic number.

It is not a de Polignac number, because 664247197 - 2²⁷ = 530029469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664247497) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332123598 + 332123599.

It is an arithmetic number, because the mean of its divisors is an integer number (332123599).

Almost surely, 2^664247197 is an apocalyptic number.

It is an amenable number.

664247197 is a deficient number, since it is larger than the sum of its proper divisors (1).

664247197 is an equidigital number, since it uses as much as digits as its factorization.

664247197 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 508032, while the sum is 46.

The square root of 664247197 is about 25772.9935591502. The cubic root of 664247197 is about 872.5223829859.

The spelling of 664247197 in words is "six hundred sixty-four million, two hundred forty-seven thousand, one hundred ninety-seven".