21325331 has 2 divisors, whose sum is σ = 21325332. Its totient is φ = 21325330.

The previous prime is 21325319. The next prime is 21325349. The reversal of 21325331 is 13352312.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21325331 is a prime.

It is a super-2 number, since 2×21325331² = 909539484519122, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21321331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10662665 + 10662666.

It is an arithmetic number, because the mean of its divisors is an integer number (10662666).

Almost surely, 2^21325331 is an apocalyptic number.

21325331 is a deficient number, since it is larger than the sum of its proper divisors (1).

21325331 is an equidigital number, since it uses as much as digits as its factorization.

21325331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 540, while the sum is 20.

The square root of 21325331 is about 4617.9357942700. The cubic root of 21325331 is about 277.3098272281.

Adding to 21325331 its reverse (13352312), we get a palindrome (34677643).

The spelling of 21325331 in words is "twenty-one million, three hundred twenty-five thousand, three hundred thirty-one".