11221220121021 has 10 divisors (see below), whose sum is σ = 16762563390782. Its totient is φ = 7480813413960.

The previous prime is 11221220120987. The next prime is 11221220121047. The reversal of 11221220121021 is 12012102212211.

11221220121021 is a `hidden beast` number, since 11 + 221 + 2 + 201 + 210 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 9650584558521 + 1570635562500 = 3106539^2 + 1253250^2 .

It is not a de Polignac number, because 11221220121021 - 2¹⁰ = 11221220119997 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11221220120985 and 11221220121003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11221220121821) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 69266790790 + ... + 69266790951.

Almost surely, 2^{11221220121021} is an apocalyptic number.

It is an amenable number.

11221220121021 is a deficient number, since it is larger than the sum of its proper divisors (5541343269761).

11221220121021 is an equidigital number, since it uses as much as digits as its factorization.

11221220121021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138533581753 (or 138533581744 counting only the distinct ones).

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

Adding to 11221220121021 its reverse (12012102212211), we get a palindrome (23233322333232).

The spelling of 11221220121021 in words is "eleven trillion, two hundred twenty-one billion, two hundred twenty million, one hundred twenty-one thousand, twenty-one".