20001111221 has 48 divisors (see below), whose sum is σ = 25718297472. Its totient is φ = 15141634560.

The previous prime is 20001111173. The next prime is 20001111233. The reversal of 20001111221 is 12211110002.

It is not a de Polignac number, because 20001111221 - 2⁶ = 20001111157 is a prime.

It is a super-2 number, since 2×20001111221² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20001111821) 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, 8106230 + ... + 8108696.

It is an arithmetic number, because the mean of its divisors is an integer number (535797864).

Almost surely, 2^20001111221 is an apocalyptic number.

It is an amenable number.

20001111221 is a deficient number, since it is larger than the sum of its proper divisors (5717186251).

20001111221 is a wasteful number, since it uses less digits than its factorization.

20001111221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2622 (or 2581 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 20001111221 its reverse (12211110002), we get a palindrome (32212221223).

The spelling of 20001111221 in words is "twenty billion, one million, one hundred eleven thousand, two hundred twenty-one".