12643434621 has 12 divisors (see below), whose sum is σ = 18443559420. Its totient is φ = 8345500800.

The previous prime is 12643434569. The next prime is 12643434623.

12643434621 is a `hidden beast` number, since 1 + 2 + 643 + 4 + 3 + 4 + 6 + 2 + 1 = 666.

12643434621 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 2 ways, for example, as 10321544025 + 2321890596 = 101595^2 + 48186^2 .

It is not a de Polignac number, because 12643434621 - 2²³ = 12635046013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12643434623) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6953676 + ... + 6955493.

It is an arithmetic number, because the mean of its divisors is an integer number (1536963285).

Almost surely, 2^12643434621 is an apocalyptic number.

It is an amenable number.

12643434621 is a deficient number, since it is larger than the sum of its proper divisors (5800124799).

12643434621 is a wasteful number, since it uses less digits than its factorization.

12643434621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13909276 (or 13909273 counting only the distinct ones).

The product of its digits is 82944, while the sum is 36.

The spelling of 12643434621 in words is "twelve billion, six hundred forty-three million, four hundred thirty-four thousand, six hundred twenty-one".