668541061 has 2 divisors, whose sum is σ = 668541062. Its totient is φ = 668541060.

The previous prime is 668541047. The next prime is 668541103. The reversal of 668541061 is 160145866.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 630964161 + 37576900 = 25119^2 + 6130^2 .

It is a cyclic number.

It is not a de Polignac number, because 668541061 - 2¹³ = 668532869 is a prime.

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 668541061.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668541361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334270530 + 334270531.

It is an arithmetic number, because the mean of its divisors is an integer number (334270531).

Almost surely, 2^668541061 is an apocalyptic number.

It is an amenable number.

668541061 is a deficient number, since it is larger than the sum of its proper divisors (1).

668541061 is an equidigital number, since it uses as much as digits as its factorization.

668541061 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 34560, while the sum is 37.

The square root of 668541061 is about 25856.1609872773. The cubic root of 668541061 is about 874.3984157696.

The spelling of 668541061 in words is "six hundred sixty-eight million, five hundred forty-one thousand, sixty-one".