12543721649 has 8 divisors (see below), whose sum is σ = 12600631680. Its totient is φ = 12486848976.

The previous prime is 12543721639. The next prime is 12543721667. The reversal of 12543721649 is 94612734521.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12543721649 - 2²⁴ = 12526944433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12543721639) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 833102 + ... + 848024.

It is an arithmetic number, because the mean of its divisors is an integer number (1575078960).

Almost surely, 2^12543721649 is an apocalyptic number.

It is an amenable number.

12543721649 is a deficient number, since it is larger than the sum of its proper divisors (56910031).

12543721649 is a wasteful number, since it uses less digits than its factorization.

12543721649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18679.

The product of its digits is 362880, while the sum is 44.

The spelling of 12543721649 in words is "twelve billion, five hundred forty-three million, seven hundred twenty-one thousand, six hundred forty-nine".