21120102212221 has 12 divisors (see below), whose sum is σ = 22437808194144. Its totient is φ = 19876011093000.

The previous prime is 21120102212197. The next prime is 21120102212257. The reversal of 21120102212221 is 12221220102112.

It is not a de Polignac number, because 21120102212221 - 2¹³ = 21120102204029 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120102212021) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 193668795 + ... + 193777816.

It is an arithmetic number, because the mean of its divisors is an integer number (1869817349512).

Almost surely, 2^{21120102212221} is an apocalyptic number.

It is an amenable number.

21120102212221 is a deficient number, since it is larger than the sum of its proper divisors (1317705981923).

21120102212221 is a wasteful number, since it uses less digits than its factorization.

21120102212221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 387446800 (or 387446781 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21120102212221 its reverse (12221220102112), we get a palindrome (33341322314333).

The spelling of 21120102212221 in words is "twenty-one trillion, one hundred twenty billion, one hundred two million, two hundred twelve thousand, two hundred twenty-one".