669440044967 has 4 divisors (see below), whose sum is σ = 673703994456. Its totient is φ = 665176095480.

The previous prime is 669440044961. The next prime is 669440044969. The reversal of 669440044967 is 769440044966.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 769440044966 = 2 ⋅384720022483.

It is a cyclic number.

It is not a de Polignac number, because 669440044967 - 2⁴ = 669440044951 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669440044961) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2131974509 + ... + 2131974822.

It is an arithmetic number, because the mean of its divisors is an integer number (168425998614).

Almost surely, 2^669440044967 is an apocalyptic number.

669440044967 is a deficient number, since it is larger than the sum of its proper divisors (4263949489).

669440044967 is a wasteful number, since it uses less digits than its factorization.

669440044967 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4263949488.

The product of its (nonzero) digits is 31352832, while the sum is 59.

Subtracting 669440044967 from its reverse (769440044966), we obtain a palindrome (99999999999).

The spelling of 669440044967 in words is "six hundred sixty-nine billion, four hundred forty million, forty-four thousand, nine hundred sixty-seven".