21330271 has 2 divisors, whose sum is σ = 21330272. Its totient is φ = 21330270.

The previous prime is 21330259. The next prime is 21330299. The reversal of 21330271 is 17203312.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21330271 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21330251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10665135 + 10665136.

It is an arithmetic number, because the mean of its divisors is an integer number (10665136).

Almost surely, 2^21330271 is an apocalyptic number.

21330271 is a deficient number, since it is larger than the sum of its proper divisors (1).

21330271 is an equidigital number, since it uses as much as digits as its factorization.

21330271 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 252, while the sum is 19.

The square root of 21330271 is about 4618.4706343118. The cubic root of 21330271 is about 277.3312384593.

Adding to 21330271 its reverse (17203312), we get a palindrome (38533583).

The spelling of 21330271 in words is "twenty-one million, three hundred thirty thousand, two hundred seventy-one".