666069601649 has 2 divisors, whose sum is σ = 666069601650. Its totient is φ = 666069601648.

The previous prime is 666069601627. The next prime is 666069601709. The reversal of 666069601649 is 946106960666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 416076601600 + 249993000049 = 645040^2 + 499993^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666069601649 is a prime.

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 (666069601619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333034800824 + 333034800825.

It is an arithmetic number, because the mean of its divisors is an integer number (333034800825).

Almost surely, 2^666069601649 is an apocalyptic number.

It is an amenable number.

666069601649 is a deficient number, since it is larger than the sum of its proper divisors (1).

666069601649 is an equidigital number, since it uses as much as digits as its factorization.

666069601649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15116544, while the sum is 59.

The spelling of 666069601649 in words is "six hundred sixty-six billion, sixty-nine million, six hundred one thousand, six hundred forty-nine".