21211000021221 has 32 divisors (see below), whose sum is σ = 29607441518592. Its totient is φ = 13481666204160.

The previous prime is 21211000021187. The next prime is 21211000021229. The reversal of 21211000021221 is 12212000011212.

It is not a de Polignac number, because 21211000021221 - 2²³ = 21210991632613 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21211000021221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211000021229) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 56100616 + ... + 56477438.

It is an arithmetic number, because the mean of its divisors is an integer number (925232547456).

Almost surely, 2^{21211000021221} is an apocalyptic number.

It is an amenable number.

21211000021221 is a deficient number, since it is larger than the sum of its proper divisors (8396441497371).

21211000021221 is a wasteful number, since it uses less digits than its factorization.

21211000021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 379513.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21211000021221 its reverse (12212000011212), we get a palindrome (33423000032433).

The spelling of 21211000021221 in words is "twenty-one trillion, two hundred eleven billion, twenty-one thousand, two hundred twenty-one".