665445197 has 2 divisors, whose sum is σ = 665445198. Its totient is φ = 665445196.

The previous prime is 665445191. The next prime is 665445241. The reversal of 665445197 is 791544566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 623700676 + 41744521 = 24974^2 + 6461^2 .

It is a cyclic number.

It is not a de Polignac number, because 665445197 - 2¹⁰ = 665444173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665445191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332722598 + 332722599.

It is an arithmetic number, because the mean of its divisors is an integer number (332722599).

Almost surely, 2^665445197 is an apocalyptic number.

It is an amenable number.

665445197 is a deficient number, since it is larger than the sum of its proper divisors (1).

665445197 is an equidigital number, since it uses as much as digits as its factorization.

665445197 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 907200, while the sum is 47.

The square root of 665445197 is about 25796.2244718098. The cubic root of 665445197 is about 873.0466125418.

The spelling of 665445197 in words is "six hundred sixty-five million, four hundred forty-five thousand, one hundred ninety-seven".