21243044201 has 2 divisors, whose sum is σ = 21243044202. Its totient is φ = 21243044200.

The previous prime is 21243044131. The next prime is 21243044203. The reversal of 21243044201 is 10244034212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19515810601 + 1727233600 = 139699^2 + 41560^2 .

It is a cyclic number.

It is not a de Polignac number, because 21243044201 - 2¹⁰ = 21243043177 is a prime.

Together with 21243044203, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21243044203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10621522100 + 10621522101.

It is an arithmetic number, because the mean of its divisors is an integer number (10621522101).

Almost surely, 2^21243044201 is an apocalyptic number.

It is an amenable number.

21243044201 is a deficient number, since it is larger than the sum of its proper divisors (1).

21243044201 is an equidigital number, since it uses as much as digits as its factorization.

21243044201 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1536, while the sum is 23.

Adding to 21243044201 its reverse (10244034212), we get a palindrome (31487078413).

The spelling of 21243044201 in words is "twenty-one billion, two hundred forty-three million, forty-four thousand, two hundred one".