21335263 has 2 divisors, whose sum is σ = 21335264. Its totient is φ = 21335262.

The previous prime is 21335261. The next prime is 21335311. The reversal of 21335263 is 36253312.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21335263 - 2¹ = 21335261 is a prime.

Together with 21335261, it forms a pair of twin primes.

It is a plaindrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21335261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10667631 + 10667632.

It is an arithmetic number, because the mean of its divisors is an integer number (10667632).

Almost surely, 2^21335263 is an apocalyptic number.

21335263 is a deficient number, since it is larger than the sum of its proper divisors (1).

21335263 is an equidigital number, since it uses as much as digits as its factorization.

21335263 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3240, while the sum is 25.

The square root of 21335263 is about 4619.0110413377. The cubic root of 21335263 is about 277.3528717140.

Adding to 21335263 its reverse (36253312), we get a palindrome (57588575).

It can be divided in two parts, 2133 and 5263, that added together give a square (7396 = 86²).

The spelling of 21335263 in words is "twenty-one million, three hundred thirty-five thousand, two hundred sixty-three".