668266246649 has 2 divisors, whose sum is σ = 668266246650. Its totient is φ = 668266246648.

The previous prime is 668266246643. The next prime is 668266246741. The reversal of 668266246649 is 946642662866.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 614224875625 + 54041371024 = 783725^2 + 232468^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-668266246649 is a prime.

It is a super-3 number, since 3×668266246649³ (a number of 36 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (668266246643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334133123324 + 334133123325.

It is an arithmetic number, because the mean of its divisors is an integer number (334133123325).

Almost surely, 2^668266246649 is an apocalyptic number.

It is an amenable number.

668266246649 is a deficient number, since it is larger than the sum of its proper divisors (1).

668266246649 is an equidigital number, since it uses as much as digits as its factorization.

668266246649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 214990848, while the sum is 65.

The spelling of 668266246649 in words is "six hundred sixty-eight billion, two hundred sixty-six million, two hundred forty-six thousand, six hundred forty-nine".