21331023233 has 4 divisors (see below), whose sum is σ = 22971871188. Its totient is φ = 19690175280.

The previous prime is 21331023209. The next prime is 21331023271. The reversal of 21331023233 is 33232013312.

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

It can be written as a sum of positive squares in 2 ways, for example, as 4182596929 + 17148426304 = 64673^2 + 130952^2 .

It is a cyclic number.

It is not a de Polignac number, because 21331023233 - 2²⁰ = 21329974657 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21331023199 and 21331023208.

It is not an unprimeable number, because it can be changed into a prime (21331023533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 820423958 + ... + 820423983.

It is an arithmetic number, because the mean of its divisors is an integer number (5742967797).

Almost surely, 2^21331023233 is an apocalyptic number.

It is an amenable number.

21331023233 is a deficient number, since it is larger than the sum of its proper divisors (1640847955).

21331023233 is a wasteful number, since it uses less digits than its factorization.

21331023233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1640847954.

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

Adding to 21331023233 its reverse (33232013312), we get a palindrome (54563036545).

The spelling of 21331023233 in words is "twenty-one billion, three hundred thirty-one million, twenty-three thousand, two hundred thirty-three".