21459211 has 2 divisors, whose sum is σ = 21459212. Its totient is φ = 21459210.

The previous prime is 21459209. The next prime is 21459239. The reversal of 21459211 is 11295412.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21459211 - 2¹ = 21459209 is a prime.

Together with 21459209, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21459281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10729605 + 10729606.

It is an arithmetic number, because the mean of its divisors is an integer number (10729606).

Almost surely, 2^21459211 is an apocalyptic number.

21459211 is a deficient number, since it is larger than the sum of its proper divisors (1).

21459211 is an equidigital number, since it uses as much as digits as its factorization.

21459211 is an evil number, because the sum of its binary digits is even.

The product of its digits is 720, while the sum is 25.

The square root of 21459211 is about 4632.4087686645. The cubic root of 21459211 is about 277.8889322201. Note that the first 3 decimals are identical.

The spelling of 21459211 in words is "twenty-one million, four hundred fifty-nine thousand, two hundred eleven".