21204403043 has 2 divisors, whose sum is σ = 21204403044. Its totient is φ = 21204403042.

The previous prime is 21204402997. The next prime is 21204403049. The reversal of 21204403043 is 34030440212.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21204403043 is a prime.

It is not a weakly prime, because it can be changed into another prime (21204403049) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10602201521 + 10602201522.

It is an arithmetic number, because the mean of its divisors is an integer number (10602201522).

Almost surely, 2^21204403043 is an apocalyptic number.

21204403043 is a deficient number, since it is larger than the sum of its proper divisors (1).

21204403043 is an equidigital number, since it uses as much as digits as its factorization.

21204403043 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 23.

Adding to 21204403043 its reverse (34030440212), we get a palindrome (55234843255).

The spelling of 21204403043 in words is "twenty-one billion, two hundred four million, four hundred three thousand, forty-three".