21331223033 has 4 divisors (see below), whose sum is σ = 21351558900. Its totient is φ = 21310887168.

The previous prime is 21331223029. The next prime is 21331223047. The reversal of 21331223033 is 33032213312.

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 14589499369 + 6741723664 = 120787^2 + 82108^2 .

It is a cyclic number.

It is not a de Polignac number, because 21331223033 - 2² = 21331223029 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21331223003) 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, 10166360 + ... + 10168457.

It is an arithmetic number, because the mean of its divisors is an integer number (5337889725).

Almost surely, 2^21331223033 is an apocalyptic number.

It is an amenable number.

21331223033 is a deficient number, since it is larger than the sum of its proper divisors (20335867).

21331223033 is a wasteful number, since it uses less digits than its factorization.

21331223033 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20335866.

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

Adding to 21331223033 its reverse (33032213312), we get a palindrome (54363436345).

The spelling of 21331223033 in words is "twenty-one billion, three hundred thirty-one million, two hundred twenty-three thousand, thirty-three".