21221110200221 has 16 divisors (see below), whose sum is σ = 23796287132544. Its totient is φ = 18819285855744.

The previous prime is 21221110200193. The next prime is 21221110200239. The reversal of 21221110200221 is 12200201112212.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21221110200221 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a self number, because there is not a number n which added to its sum of digits gives 21221110200221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221110200281) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 405003200 + ... + 405055593.

It is an arithmetic number, because the mean of its divisors is an integer number (1487267945784).

Almost surely, 2^{21221110200221} is an apocalyptic number.

It is an amenable number.

21221110200221 is a deficient number, since it is larger than the sum of its proper divisors (2575176932323).

21221110200221 is a wasteful number, since it uses less digits than its factorization.

21221110200221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 810058900.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21221110200221 its reverse (12200201112212), we get a palindrome (33421311312433).

The spelling of 21221110200221 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred ten million, two hundred thousand, two hundred twenty-one".