21200100221 has 8 divisors (see below), whose sum is σ = 21637509120. Its totient is φ = 20766917808.

The previous prime is 21200100217. The next prime is 21200100227. The reversal of 21200100221 is 12200100212.

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 21200100221 - 2² = 21200100217 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200100227) 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, 1046486 + ... + 1066551.

It is an arithmetic number, because the mean of its divisors is an integer number (2704688640).

Almost surely, 2^21200100221 is an apocalyptic number.

It is an amenable number.

21200100221 is a deficient number, since it is larger than the sum of its proper divisors (437408899).

21200100221 is a wasteful number, since it uses less digits than its factorization.

21200100221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2113243.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21200100221 its reverse (12200100212), we get a palindrome (33400200433).

Subtracting from 21200100221 its reverse (12200100212), we obtain a palindrome (9000000009).

The spelling of 21200100221 in words is "twenty-one billion, two hundred million, one hundred thousand, two hundred twenty-one".