21323303231 has 4 divisors (see below), whose sum is σ = 21358902000. Its totient is φ = 21287704464.

The previous prime is 21323303227. The next prime is 21323303233. The reversal of 21323303231 is 13230332312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21323303231 - 2² = 21323303227 is a prime.

It is a super-2 number, since 2×21323303231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21323303197 and 21323303206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21323303233) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17798486 + ... + 17799683.

It is an arithmetic number, because the mean of its divisors is an integer number (5339725500).

Almost surely, 2^21323303231 is an apocalyptic number.

21323303231 is a deficient number, since it is larger than the sum of its proper divisors (35598769).

21323303231 is an equidigital number, since it uses as much as digits as its factorization.

21323303231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35598768.

The product of its (nonzero) digits is 1944, while the sum is 23.

Adding to 21323303231 its reverse (13230332312), we get a palindrome (34553635543).

The spelling of 21323303231 in words is "twenty-one billion, three hundred twenty-three million, three hundred three thousand, two hundred thirty-one".