12643021 has 2 divisors, whose sum is σ = 12643022. Its totient is φ = 12643020.

The previous prime is 12643003. The next prime is 12643049. The reversal of 12643021 is 12034621.

12643021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10989225 + 1653796 = 3315^2 + 1286^2 .

It is an emirp because it is prime and its reverse (12034621) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12643021 - 2¹¹ = 12640973 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12643021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12640021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6321510 + 6321511.

It is an arithmetic number, because the mean of its divisors is an integer number (6321511).

Almost surely, 2^12643021 is an apocalyptic number.

It is an amenable number.

12643021 is a deficient number, since it is larger than the sum of its proper divisors (1).

12643021 is an equidigital number, since it uses as much as digits as its factorization.

12643021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 12643021 is about 3555.7026028621. The cubic root of 12643021 is about 232.9612134348.

Adding to 12643021 its reverse (12034621), we get a palindrome (24677642).

Subtracting from 12643021 its reverse (12034621), we obtain a square (608400 = 780²).

The spelling of 12643021 in words is "twelve million, six hundred forty-three thousand, twenty-one".