21102012211221 has 16 divisors (see below), whose sum is σ = 31792108795200. Its totient is φ = 13829567323824.

The previous prime is 21102012211153. The next prime is 21102012211229. The reversal of 21102012211221 is 12211221020112.

21102012211221 is a `hidden beast` number, since 21 + 1 + 0 + 201 + 221 + 1 + 221 = 666.

It is not a de Polignac number, because 21102012211221 - 2¹⁵ = 21102012178453 is a prime.

It is a super-3 number, since 3×21102012211221³ (a number of 41 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21102012211194 and 21102012211203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102012211229) 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, 6623354406 + ... + 6623357591.

It is an arithmetic number, because the mean of its divisors is an integer number (1987006799700).

Almost surely, 2^{21102012211221} is an apocalyptic number.

It is an amenable number.

21102012211221 is a deficient number, since it is larger than the sum of its proper divisors (10690096583979).

21102012211221 is a wasteful number, since it uses less digits than its factorization.

21102012211221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13246712065 (or 13246712059 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21102012211221 its reverse (12211221020112), we get a palindrome (33313233231333).

The spelling of 21102012211221 in words is "twenty-one trillion, one hundred two billion, twelve million, two hundred eleven thousand, two hundred twenty-one".