669744447947 has 2 divisors, whose sum is σ = 669744447948. Its totient is φ = 669744447946.

The previous prime is 669744447907. The next prime is 669744448007. The reversal of 669744447947 is 749744447966.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 669744447947 - 2²⁶ = 669677339083 is a prime.

It is not a weakly prime, because it can be changed into another prime (669744447907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334872223973 + 334872223974.

It is an arithmetic number, because the mean of its divisors is an integer number (334872223974).

Almost surely, 2^669744447947 is an apocalyptic number.

669744447947 is a deficient number, since it is larger than the sum of its proper divisors (1).

669744447947 is an equidigital number, since it uses as much as digits as its factorization.

669744447947 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1024192512, while the sum is 71.

The spelling of 669744447947 in words is "six hundred sixty-nine billion, seven hundred forty-four million, four hundred forty-seven thousand, nine hundred forty-seven".