21333271 has 2 divisors, whose sum is σ = 21333272. Its totient is φ = 21333270.

The previous prime is 21333251. The next prime is 21333329. The reversal of 21333271 is 17233312.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21333271 - 2¹⁷ = 21202199 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21333251) 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, 10666635 + 10666636.

It is an arithmetic number, because the mean of its divisors is an integer number (10666636).

Almost surely, 2^21333271 is an apocalyptic number.

21333271 is a deficient number, since it is larger than the sum of its proper divisors (1).

21333271 is an equidigital number, since it uses as much as digits as its factorization.

21333271 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 756, while the sum is 22.

The square root of 21333271 is about 4618.7954057308. The cubic root of 21333271 is about 277.3442396180.

Adding to 21333271 its reverse (17233312), we get a palindrome (38566583).

The spelling of 21333271 in words is "twenty-one million, three hundred thirty-three thousand, two hundred seventy-one".