668676641 has 2 divisors, whose sum is σ = 668676642. Its totient is φ = 668676640.

The previous prime is 668676553. The next prime is 668676643. The reversal of 668676641 is 146676866.

It is a happy number.

668676641 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., 631466641 + 37210000 = 25129^2 + 6100^2 .

It is a cyclic number.

It is not a de Polignac number, because 668676641 - 2¹⁰ = 668675617 is a prime.

Together with 668676643, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 668676641.

It is not a weakly prime, because it can be changed into another prime (668676643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334338320 + 334338321.

It is an arithmetic number, because the mean of its divisors is an integer number (334338321).

Almost surely, 2^668676641 is an apocalyptic number.

It is an amenable number.

668676641 is a deficient number, since it is larger than the sum of its proper divisors (1).

668676641 is an equidigital number, since it uses as much as digits as its factorization.

668676641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1741824, while the sum is 50.

The square root of 668676641 is about 25858.7826666299. The cubic root of 668676641 is about 874.4575210517.

The spelling of 668676641 in words is "six hundred sixty-eight million, six hundred seventy-six thousand, six hundred forty-one".