21203242043 has 2 divisors, whose sum is σ = 21203242044. Its totient is φ = 21203242042.

The previous prime is 21203242031. The next prime is 21203242199. The reversal of 21203242043 is 34024230212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21203242043 - 2²² = 21199047739 is a prime.

It is not a weakly prime, because it can be changed into another prime (21203242013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601621021 + 10601621022.

It is an arithmetic number, because the mean of its divisors is an integer number (10601621022).

Almost surely, 2^21203242043 is an apocalyptic number.

21203242043 is a deficient number, since it is larger than the sum of its proper divisors (1).

21203242043 is an equidigital number, since it uses as much as digits as its factorization.

21203242043 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 21203242043 its reverse (34024230212), we get a palindrome (55227472255).

The spelling of 21203242043 in words is "twenty-one billion, two hundred three million, two hundred forty-two thousand, forty-three".