21330259 has 2 divisors, whose sum is σ = 21330260. Its totient is φ = 21330258.

The previous prime is 21330251. The next prime is 21330271. The reversal of 21330259 is 95203312.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21330259 - 2³ = 21330251 is a prime.

It is not a weakly prime, because it can be changed into another prime (21330251) 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, 10665129 + 10665130.

It is an arithmetic number, because the mean of its divisors is an integer number (10665130).

Almost surely, 2^21330259 is an apocalyptic number.

21330259 is a deficient number, since it is larger than the sum of its proper divisors (1).

21330259 is an equidigital number, since it uses as much as digits as its factorization.

21330259 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1620, while the sum is 25.

The square root of 21330259 is about 4618.4693351802. The cubic root of 21330259 is about 277.3311864522.

The spelling of 21330259 in words is "twenty-one million, three hundred thirty thousand, two hundred fifty-nine".