21323404423 has 2 divisors, whose sum is σ = 21323404424. Its totient is φ = 21323404422.

The previous prime is 21323404411. The next prime is 21323404439. The reversal of 21323404423 is 32440432312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21323404423 - 2⁵ = 21323404391 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21323404391 and 21323404400.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21323404483) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10661702211 + 10661702212.

It is an arithmetic number, because the mean of its divisors is an integer number (10661702212).

Almost surely, 2^21323404423 is an apocalyptic number.

21323404423 is a deficient number, since it is larger than the sum of its proper divisors (1).

21323404423 is an equidigital number, since it uses as much as digits as its factorization.

21323404423 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13824, while the sum is 28.

Adding to 21323404423 its reverse (32440432312), we get a palindrome (53763836735).

The spelling of 21323404423 in words is "twenty-one billion, three hundred twenty-three million, four hundred four thousand, four hundred twenty-three".