21231330233 has 4 divisors (see below), whose sum is σ = 21264145920. Its totient is φ = 21198514548.

The previous prime is 21231330217. The next prime is 21231330259. The reversal of 21231330233 is 33203313212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21231330233 - 2⁴ = 21231330217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21231330199 and 21231330208.

It is not an unprimeable number, because it can be changed into a prime (21231330833) 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, 16406873 + ... + 16408166.

It is an arithmetic number, because the mean of its divisors is an integer number (5316036480).

Almost surely, 2^21231330233 is an apocalyptic number.

It is an amenable number.

21231330233 is a deficient number, since it is larger than the sum of its proper divisors (32815687).

21231330233 is an equidigital number, since it uses as much as digits as its factorization.

21231330233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32815686.

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

Adding to 21231330233 its reverse (33203313212), we get a palindrome (54434643445).

The spelling of 21231330233 in words is "twenty-one billion, two hundred thirty-one million, three hundred thirty thousand, two hundred thirty-three".