21203134423 has 2 divisors, whose sum is σ = 21203134424. Its totient is φ = 21203134422.

The previous prime is 21203134411. The next prime is 21203134471. The reversal of 21203134423 is 32443130212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21203134423 - 2⁹ = 21203133911 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21203104423) 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, 10601567211 + 10601567212.

It is an arithmetic number, because the mean of its divisors is an integer number (10601567212).

Almost surely, 2^21203134423 is an apocalyptic number.

21203134423 is a deficient number, since it is larger than the sum of its proper divisors (1).

21203134423 is an equidigital number, since it uses as much as digits as its factorization.

21203134423 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 25.

Adding to 21203134423 its reverse (32443130212), we get a palindrome (53646264635).

The spelling of 21203134423 in words is "twenty-one billion, two hundred three million, one hundred thirty-four thousand, four hundred twenty-three".