21255322423 has 2 divisors, whose sum is σ = 21255322424. Its totient is φ = 21255322422.

The previous prime is 21255322421. The next prime is 21255322463. The reversal of 21255322423 is 32422355212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21255322423 - 2¹ = 21255322421 is a prime.

Together with 21255322421, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21255322421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10627661211 + 10627661212.

It is an arithmetic number, because the mean of its divisors is an integer number (10627661212).

Almost surely, 2^21255322423 is an apocalyptic number.

21255322423 is a deficient number, since it is larger than the sum of its proper divisors (1).

21255322423 is an equidigital number, since it uses as much as digits as its factorization.

21255322423 is an evil number, because the sum of its binary digits is even.

The product of its digits is 28800, while the sum is 31.

Adding to 21255322423 its reverse (32422355212), we get a palindrome (53677677635).

The spelling of 21255322423 in words is "twenty-one billion, two hundred fifty-five million, three hundred twenty-two thousand, four hundred twenty-three".