21330211 has 8 divisors (see below), whose sum is σ = 24791040. Its totient is φ = 17972808.

The previous prime is 21330163. The next prime is 21330251. The reversal of 21330211 is 11203312.

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

It is not a de Polignac number, because 21330211 - 2⁷ = 21330083 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21330191 and 21330200.

It is not an unprimeable number, because it can be changed into a prime (21330251) 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, 25411 + ... + 26236.

It is an arithmetic number, because the mean of its divisors is an integer number (3098880).

Almost surely, 2^21330211 is an apocalyptic number.

21330211 is a deficient number, since it is larger than the sum of its proper divisors (3460829).

21330211 is an equidigital number, since it uses as much as digits as its factorization.

21330211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51713.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 21330211 is about 4618.4641386504. The cubic root of 21330211 is about 277.3309784237.

Adding to 21330211 its reverse (11203312), we get a palindrome (32533523).

The spelling of 21330211 in words is "twenty-one million, three hundred thirty thousand, two hundred eleven".