21331323 has 16 divisors (see below), whose sum is σ = 34033440. Its totient is φ = 13126752.

The previous prime is 21331313. The next prime is 21331333. The reversal of 21331323 is 32313312.

It is an interprime number because it is at equal distance from previous prime (21331313) and next prime (21331333).

It is not a de Polignac number, because 21331323 - 2⁸ = 21331067 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21331296 and 21331305.

It is not an unprimeable number, because it can be changed into a prime (21331313) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30036 + ... + 30737.

It is an arithmetic number, because the mean of its divisors is an integer number (2127090).

Almost surely, 2^21331323 is an apocalyptic number.

21331323 is a deficient number, since it is larger than the sum of its proper divisors (12702117).

21331323 is a wasteful number, since it uses less digits than its factorization.

21331323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60795 (or 60789 counting only the distinct ones).

The product of its digits is 324, while the sum is 18.

The square root of 21331323 is about 4618.5845234227. The cubic root of 21331323 is about 277.3357976711.

Adding to 21331323 its reverse (32313312), we get a palindrome (53644635).

The spelling of 21331323 in words is "twenty-one million, three hundred thirty-one thousand, three hundred twenty-three".