21002211201221 has 8 divisors (see below), whose sum is σ = 21456274922880. Its totient is φ = 20552852803392.

The previous prime is 21002211201211. The next prime is 21002211201239. The reversal of 21002211201221 is 12210211220012.

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 21002211201221 - 2¹⁴ = 21002211184837 is a prime.

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 21002211201221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002211201211) 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, 1176321935 + ... + 1176339788.

It is an arithmetic number, because the mean of its divisors is an integer number (2682034365360).

Almost surely, 2^{21002211201221} is an apocalyptic number.

It is an amenable number.

21002211201221 is a deficient number, since it is larger than the sum of its proper divisors (454063721659).

21002211201221 is a wasteful number, since it uses less digits than its factorization.

21002211201221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2352661915.

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

Adding to 21002211201221 its reverse (12210211220012), we get a palindrome (33212422421233).

The spelling of 21002211201221 in words is "twenty-one trillion, two billion, two hundred eleven million, two hundred one thousand, two hundred twenty-one".