21002222100221 has 8 divisors (see below), whose sum is σ = 21687520107264. Its totient is φ = 20317412028960.

The previous prime is 21002222100217. The next prime is 21002222100253. The reversal of 21002222100221 is 12200122220012.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21002222100221 - 2² = 21002222100217 is a prime.

It is a super-2 number, since 2×21002222100221² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21002222100221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002222109221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 121896455 + ... + 122068628.

It is an arithmetic number, because the mean of its divisors is an integer number (2710940013408).

Almost surely, 2^{21002222100221} is an apocalyptic number.

It is an amenable number.

21002222100221 is a deficient number, since it is larger than the sum of its proper divisors (685298007043).

21002222100221 is a wasteful number, since it uses less digits than its factorization.

21002222100221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243967891.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21002222100221 its reverse (12200122220012), we get a palindrome (33202344320233).

The spelling of 21002222100221 in words is "twenty-one trillion, two billion, two hundred twenty-two million, one hundred thousand, two hundred twenty-one".