12663497721 has 48 divisors (see below), whose sum is σ = 20146182144. Its totient is φ = 7051103136.

The previous prime is 12663497689. The next prime is 12663497741. The reversal of 12663497721 is 12779436621.

It is not a de Polignac number, because 12663497721 - 2⁵ = 12663497689 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12663497741) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2924460 + ... + 2928786.

It is an arithmetic number, because the mean of its divisors is an integer number (419712128).

Almost surely, 2^12663497721 is an apocalyptic number.

It is an amenable number.

12663497721 is a deficient number, since it is larger than the sum of its proper divisors (7482684423).

12663497721 is a wasteful number, since it uses less digits than its factorization.

12663497721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4850 (or 4843 counting only the distinct ones).

The product of its digits is 762048, while the sum is 48.

The spelling of 12663497721 in words is "twelve billion, six hundred sixty-three million, four hundred ninety-seven thousand, seven hundred twenty-one".