20011111221 has 16 divisors (see below), whose sum is σ = 26741145600. Its totient is φ = 13310942400.

The previous prime is 20011111207. The next prime is 20011111223. The reversal of 20011111221 is 12211111002.

It is not a de Polignac number, because 20011111221 - 2⁶ = 20011111157 is a prime.

It is a super-2 number, since 2×20011111221² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20011111197 and 20011111206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20011111223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3254476 + ... + 3260618.

It is an arithmetic number, because the mean of its divisors is an integer number (1671321600).

Almost surely, 2^20011111221 is an apocalyptic number.

It is an amenable number.

20011111221 is a deficient number, since it is larger than the sum of its proper divisors (6730034379).

20011111221 is a wasteful number, since it uses less digits than its factorization.

20011111221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8396.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 20011111221 its reverse (12211111002), we get a palindrome (32222222223).

The spelling of 20011111221 in words is "twenty billion, eleven million, one hundred eleven thousand, two hundred twenty-one".