21241331 has 2 divisors, whose sum is σ = 21241332. Its totient is φ = 21241330.

The previous prime is 21241327. The next prime is 21241333. The reversal of 21241331 is 13314212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21241331 - 2² = 21241327 is a prime.

It is a super-2 number, since 2×21241331² = 902388285303122, which contains 22 as substring.

Together with 21241333, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21241333) 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, 10620665 + 10620666.

It is an arithmetic number, because the mean of its divisors is an integer number (10620666).

Almost surely, 2^21241331 is an apocalyptic number.

21241331 is a deficient number, since it is larger than the sum of its proper divisors (1).

21241331 is an equidigital number, since it uses as much as digits as its factorization.

21241331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 144, while the sum is 17.

The square root of 21241331 is about 4608.8318476594. The cubic root of 21241331 is about 276.9452423834.

Adding to 21241331 its reverse (13314212), we get a palindrome (34555543).

The spelling of 21241331 in words is "twenty-one million, two hundred forty-one thousand, three hundred thirty-one".