21001021002211 has 4 divisors (see below), whose sum is σ = 21397266681552. Its totient is φ = 20604775322872.

The previous prime is 21001021002197. The next prime is 21001021002239. The reversal of 21001021002211 is 11220012010012.

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 21001021002211 - 2⁵ = 21001021002179 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21001021002191 and 21001021002200.

It is not an unprimeable number, because it can be changed into a prime (21001021302211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 198122839591 + ... + 198122839696.

It is an arithmetic number, because the mean of its divisors is an integer number (5349316670388).

Almost surely, 2^{21001021002211} is an apocalyptic number.

21001021002211 is a deficient number, since it is larger than the sum of its proper divisors (396245679341).

21001021002211 is an equidigital number, since it uses as much as digits as its factorization.

21001021002211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396245679340.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21001021002211 its reverse (11220012010012), we get a palindrome (32221033012223).

The spelling of 21001021002211 in words is "twenty-one trillion, one billion, twenty-one million, two thousand, two hundred eleven".