668999293 has 2 divisors, whose sum is σ = 668999294. Its totient is φ = 668999292.

The previous prime is 668999273. The next prime is 668999299. The reversal of 668999293 is 392999866.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 624350169 + 44649124 = 24987^2 + 6682^2 .

It is a cyclic number.

It is not a de Polignac number, because 668999293 - 2¹³ = 668991101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668999299) 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, 334499646 + 334499647.

It is an arithmetic number, because the mean of its divisors is an integer number (334499647).

Almost surely, 2^668999293 is an apocalyptic number.

It is an amenable number.

668999293 is a deficient number, since it is larger than the sum of its proper divisors (1).

668999293 is an equidigital number, since it uses as much as digits as its factorization.

668999293 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11337408, while the sum is 61.

The square root of 668999293 is about 25865.0206456519. The cubic root of 668999293 is about 874.5981471194.

The spelling of 668999293 in words is "six hundred sixty-eight million, nine hundred ninety-nine thousand, two hundred ninety-three".