669993543821 has 16 divisors (see below), whose sum is σ = 808276128000. Its totient is φ = 554477407344.

The previous prime is 669993543803. The next prime is 669993543917. The reversal of 669993543821 is 128345399966.

It is not a de Polignac number, because 669993543821 - 2³⁰ = 668919801997 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 (669993543421) 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 in 15 ways as a sum of consecutive naturals, for example, 33668225 + ... + 33688118.

It is an arithmetic number, because the mean of its divisors is an integer number (50517258000).

Almost surely, 2^669993543821 is an apocalyptic number.

It is an amenable number.

669993543821 is a deficient number, since it is larger than the sum of its proper divisors (138282584179).

669993543821 is an equidigital number, since it uses as much as digits as its factorization.

669993543821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67356393 (or 67356379 counting only the distinct ones).

The product of its digits is 75582720, while the sum is 65.

The spelling of 669993543821 in words is "six hundred sixty-nine billion, nine hundred ninety-three million, five hundred forty-three thousand, eight hundred twenty-one".