21002221011111 has 4 divisors (see below), whose sum is σ = 28002961348152. Its totient is φ = 14001480674072.

The previous prime is 21002221011097. The next prime is 21002221011139. The reversal of 21002221011111 is 11111012220012.

It is a happy number.

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 21002221011111 - 2¹⁰ = 21002221010087 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002221016111) 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, 3500370168516 + ... + 3500370168521.

It is an arithmetic number, because the mean of its divisors is an integer number (7000740337038).

Almost surely, 2^{21002221011111} is an apocalyptic number.

21002221011111 is a deficient number, since it is larger than the sum of its proper divisors (7000740337041).

21002221011111 is an equidigital number, since it uses as much as digits as its factorization.

21002221011111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7000740337040.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21002221011111 its reverse (11111012220012), we get a palindrome (32113233231123).

The spelling of 21002221011111 in words is "twenty-one trillion, two billion, two hundred twenty-one million, eleven thousand, one hundred eleven".