21201111100221 has 8 divisors (see below), whose sum is σ = 30442621067040. Its totient is φ = 13046837600112.

The previous prime is 21201111100219. The next prime is 21201111100241. The reversal of 21201111100221 is 12200111110212.

It is a happy number.

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

It is not a de Polignac number, because 21201111100221 - 2¹ = 21201111100219 is a prime.

It is a super-2 number, since 2×21201111100221² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21201111100221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201111100241) 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, 271809116631 + ... + 271809116708.

It is an arithmetic number, because the mean of its divisors is an integer number (3805327633380).

Almost surely, 2^{21201111100221} is an apocalyptic number.

It is an amenable number.

21201111100221 is a deficient number, since it is larger than the sum of its proper divisors (9241509966819).

21201111100221 is a wasteful number, since it uses less digits than its factorization.

21201111100221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 543618233355.

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

Adding to 21201111100221 its reverse (12200111110212), we get a palindrome (33401222210433).

Subtracting from 21201111100221 its reverse (12200111110212), we obtain a palindrome (9000999990009).

The spelling of 21201111100221 in words is "twenty-one trillion, two hundred one billion, one hundred eleven million, one hundred thousand, two hundred twenty-one".