21322331 has 2 divisors, whose sum is σ = 21322332. Its totient is φ = 21322330.

The previous prime is 21322319. The next prime is 21322361. The reversal of 21322331 is 13322312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21322331 - 2¹⁸ = 21060187 is a prime.

It is a super-2 number, since 2×21322331² = 909283598547122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21322361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10661165 + 10661166.

It is an arithmetic number, because the mean of its divisors is an integer number (10661166).

Almost surely, 2^21322331 is an apocalyptic number.

21322331 is a deficient number, since it is larger than the sum of its proper divisors (1).

21322331 is an equidigital number, since it uses as much as digits as its factorization.

21322331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 216, while the sum is 17.

The square root of 21322331 is about 4617.6109623917. The cubic root of 21322331 is about 277.2968228423.

Adding to 21322331 its reverse (13322312), we get a palindrome (34644643).

The spelling of 21322331 in words is "twenty-one million, three hundred twenty-two thousand, three hundred thirty-one".