668701489 has 2 divisors, whose sum is σ = 668701490. Its totient is φ = 668701488.

The previous prime is 668701487. The next prime is 668701499. The reversal of 668701489 is 984107866.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 408363264 + 260338225 = 20208^2 + 16135^2 .

It is a cyclic number.

It is not a de Polignac number, because 668701489 - 2¹ = 668701487 is a prime.

Together with 668701487, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (668701487) 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, 334350744 + 334350745.

It is an arithmetic number, because the mean of its divisors is an integer number (334350745).

Almost surely, 2^668701489 is an apocalyptic number.

It is an amenable number.

668701489 is a deficient number, since it is larger than the sum of its proper divisors (1).

668701489 is an equidigital number, since it uses as much as digits as its factorization.

668701489 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 580608, while the sum is 49.

The square root of 668701489 is about 25859.2631178849. The cubic root of 668701489 is about 874.4683525209.

The spelling of 668701489 in words is "six hundred sixty-eight million, seven hundred one thousand, four hundred eighty-nine".