12721647843 has 24 divisors (see below), whose sum is σ = 18620638400. Its totient is φ = 8368199424.

The previous prime is 12721647821. The next prime is 12721647853. The reversal of 12721647843 is 34874612721.

12721647843 is a `hidden beast` number, since 127 + 2 + 16 + 478 + 43 = 666.

It is not a de Polignac number, because 12721647843 - 2¹⁷ = 12721516771 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12721647853) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1258413 + ... + 1268481.

Almost surely, 2^12721647843 is an apocalyptic number.

12721647843 is a deficient number, since it is larger than the sum of its proper divisors (5898990557).

12721647843 is a wasteful number, since it uses less digits than its factorization.

12721647843 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11931 (or 11928 counting only the distinct ones).

The product of its digits is 451584, while the sum is 45.

The spelling of 12721647843 in words is "twelve billion, seven hundred twenty-one million, six hundred forty-seven thousand, eight hundred forty-three".