21382271 has 2 divisors, whose sum is σ = 21382272. Its totient is φ = 21382270.

The previous prime is 21382247. The next prime is 21382297. The reversal of 21382271 is 17228312.

It is an a-pointer prime, because the next prime (21382297) can be obtained adding 21382271 to its sum of digits (26).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21382271 - 2¹⁴ = 21365887 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21382271.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21382241) 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, 10691135 + 10691136.

It is an arithmetic number, because the mean of its divisors is an integer number (10691136).

Almost surely, 2^21382271 is an apocalyptic number.

21382271 is a deficient number, since it is larger than the sum of its proper divisors (1).

21382271 is an equidigital number, since it uses as much as digits as its factorization.

21382271 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1344, while the sum is 26.

The square root of 21382271 is about 4624.0967766689. The cubic root of 21382271 is about 277.5564195540.

The spelling of 21382271 in words is "twenty-one million, three hundred eighty-two thousand, two hundred seventy-one".