20111221220121 has 24 divisors (see below), whose sum is σ = 29073725591040. Its totient is φ = 13396320240576.

The previous prime is 20111221220023. The next prime is 20111221220141. The reversal of 20111221220121 is 12102212211102.

20111221220121 is a `hidden beast` number, since 201 + 1 + 1 + 221 + 220 + 1 + 21 = 666.

It is not a de Polignac number, because 20111221220121 - 2²² = 20111217025817 is a prime.

It is a super-3 number, since 3×20111221220121³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 20111221220094 and 20111221220103.

It is not an unprimeable number, because it can be changed into a prime (20111221220141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 267516280 + ... + 267591446.

It is an arithmetic number, because the mean of its divisors is an integer number (1211405232960).

Almost surely, 2^{20111221220121} is an apocalyptic number.

It is an amenable number.

20111221220121 is a deficient number, since it is larger than the sum of its proper divisors (8962504370919).

20111221220121 is a wasteful number, since it uses less digits than its factorization.

20111221220121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99525 (or 99522 counting only the distinct ones).

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

Adding to 20111221220121 its reverse (12102212211102), we get a palindrome (32213433431223).

The spelling of 20111221220121 in words is "twenty trillion, one hundred eleven billion, two hundred twenty-one million, two hundred twenty thousand, one hundred twenty-one".