21244211 has 8 divisors (see below), whose sum is σ = 22226400. Its totient is φ = 20278720.

The previous prime is 21244199. The next prime is 21244213. The reversal of 21244211 is 11244212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21244211 - 2¹⁸ = 20982067 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21244211.

It is not an unprimeable number, because it can be changed into a prime (21244213) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1535 + ... + 6696.

It is an arithmetic number, because the mean of its divisors is an integer number (2778300).

Almost surely, 2^21244211 is an apocalyptic number.

21244211 is a deficient number, since it is larger than the sum of its proper divisors (982189).

21244211 is an equidigital number, since it uses as much as digits as its factorization.

21244211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8349.

The product of its digits is 128, while the sum is 17.

The square root of 21244211 is about 4609.1442806664. The cubic root of 21244211 is about 276.9577583325.

Adding to 21244211 its reverse (11244212), we get a palindrome (32488423).

Subtracting from 21244211 its reverse (11244212), we obtain a palindrome (9999999).

The spelling of 21244211 in words is "twenty-one million, two hundred forty-four thousand, two hundred eleven".