20110221211221 has 40 divisors (see below), whose sum is σ = 30552804632504. Its totient is φ = 13178767754880.

The previous prime is 20110221211207. The next prime is 20110221211237. The reversal of 20110221211221 is 12211212201102.

20110221211221 is a `hidden beast` number, since 2 + 0 + 1 + 10 + 221 + 211 + 221 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 2450383236900 + 17659837974321 = 1565370^2 + 4202361^2 .

It is not a de Polignac number, because 20110221211221 - 2¹⁰ = 20110221210197 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20110221211194 and 20110221211203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20110221211721) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 6616491 + ... + 9165063.

Almost surely, 2^{20110221211221} is an apocalyptic number.

It is an amenable number.

20110221211221 is a deficient number, since it is larger than the sum of its proper divisors (10442583421283).

20110221211221 is a wasteful number, since it uses less digits than its factorization.

20110221211221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2550243 (or 2550234 counting only the distinct ones).

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

Adding to 20110221211221 its reverse (12211212201102), we get a palindrome (32321433412323).

The spelling of 20110221211221 in words is "twenty trillion, one hundred ten billion, two hundred twenty-one million, two hundred eleven thousand, two hundred twenty-one".