21002113221221 has 8 divisors (see below), whose sum is σ = 22911633225504. Its totient is φ = 19092632714320.

The previous prime is 21002113221163. The next prime is 21002113221227. The reversal of 21002113221221 is 12212231120012.

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

It is not a de Polignac number, because 21002113221221 - 2⁶ = 21002113221157 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21002113221193 and 21002113221202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002113221227) 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, 8757035 + ... + 10894488.

It is an arithmetic number, because the mean of its divisors is an integer number (2863954153188).

Almost surely, 2^{21002113221221} is an apocalyptic number.

It is an amenable number.

21002113221221 is a deficient number, since it is larger than the sum of its proper divisors (1909520004283).

21002113221221 is a wasteful number, since it uses less digits than its factorization.

21002113221221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19748691.

The product of its (nonzero) digits is 192, while the sum is 20.

Adding to 21002113221221 its reverse (12212231120012), we get a palindrome (33214344341233).

The spelling of 21002113221221 in words is "twenty-one trillion, two billion, one hundred thirteen million, two hundred twenty-one thousand, two hundred twenty-one".