21210133211 has 4 divisors (see below), whose sum is σ = 21216126624. Its totient is φ = 21204139800.

The previous prime is 21210133207. The next prime is 21210133237. The reversal of 21210133211 is 11233101212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21210133211 - 2² = 21210133207 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 21210133211.

It is not an unprimeable number, because it can be changed into a prime (21210133291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2991395 + ... + 2998476.

It is an arithmetic number, because the mean of its divisors is an integer number (5304031656).

Almost surely, 2^21210133211 is an apocalyptic number.

21210133211 is a deficient number, since it is larger than the sum of its proper divisors (5993413).

21210133211 is an equidigital number, since it uses as much as digits as its factorization.

21210133211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5993412.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 21210133211 its reverse (11233101212), we get a palindrome (32443234423).

The spelling of 21210133211 in words is "twenty-one billion, two hundred ten million, one hundred thirty-three thousand, two hundred eleven".