20111221001221 has 48 divisors (see below), whose sum is σ = 23565437568640. Its totient is φ = 16808407407360.

The previous prime is 20111221001177. The next prime is 20111221001299. The reversal of 20111221001221 is 12210012211102.

It is not a de Polignac number, because 20111221001221 - 2¹¹ = 20111220999173 is a prime.

It is a super-2 number, since 2×20111221001221² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20111221001195 and 20111221001204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20111221011221) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4766819650 + ... + 4766823868.

Almost surely, 2^{20111221001221} is an apocalyptic number.

It is an amenable number.

20111221001221 is a deficient number, since it is larger than the sum of its proper divisors (3454216567419).

20111221001221 is an equidigital number, since it uses as much as digits as its factorization.

20111221001221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5006 (or 4833 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 20111221001221 its reverse (12210012211102), we get a palindrome (32321233212323).

The spelling of 20111221001221 in words is "twenty trillion, one hundred eleven billion, two hundred twenty-one million, one thousand, two hundred twenty-one".