12543721651 has 8 divisors (see below), whose sum is σ = 12844121840. Its totient is φ = 12243716352.

The previous prime is 12543721639. The next prime is 12543721667. The reversal of 12543721651 is 15612734521.

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 12543721651 - 2²¹ = 12541624499 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12543721651.

It is not an unprimeable number, because it can be changed into a prime (12543721621) 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, 33930 + ... + 161983.

It is an arithmetic number, because the mean of its divisors is an integer number (1605515230).

Almost surely, 2^12543721651 is an apocalyptic number.

12543721651 is a deficient number, since it is larger than the sum of its proper divisors (300400189).

12543721651 is a wasteful number, since it uses less digits than its factorization.

12543721651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197445.

The product of its digits is 50400, while the sum is 37.

The spelling of 12543721651 in words is "twelve billion, five hundred forty-three million, seven hundred twenty-one thousand, six hundred fifty-one".