666488609 has 2 divisors, whose sum is σ = 666488610. Its totient is φ = 666488608.

The previous prime is 666488539. The next prime is 666488629. The reversal of 666488609 is 906884666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 375274384 + 291214225 = 19372^2 + 17065^2 .

It is a cyclic number.

It is not a de Polignac number, because 666488609 - 2¹² = 666484513 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (666488629) 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, 333244304 + 333244305.

It is an arithmetic number, because the mean of its divisors is an integer number (333244305).

Almost surely, 2^666488609 is an apocalyptic number.

It is an amenable number.

666488609 is a deficient number, since it is larger than the sum of its proper divisors (1).

666488609 is an equidigital number, since it uses as much as digits as its factorization.

666488609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2985984, while the sum is 53.

The square root of 666488609 is about 25816.4406725637. The cubic root of 666488609 is about 873.5026839616.

It can be divided in two parts, 66648 and 8609, that added together give a palindrome (75257).

The spelling of 666488609 in words is "six hundred sixty-six million, four hundred eighty-eight thousand, six hundred nine".