20021111220 has 96 divisors (see below), whose sum is σ = 61222283136. Its totient is φ = 4848294400.

The previous prime is 20021111161. The next prime is 20021111239. The reversal of 20021111220 is 2211112002.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 20021111196 and 20021111205.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 604942 + ... + 637178.

It is an arithmetic number, because the mean of its divisors is an integer number (637732116).

Almost surely, 2^20021111220 is an apocalyptic number.

20021111220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20021111220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30611141568).

20021111220 is an abundant number, since it is smaller than the sum of its proper divisors (41201171916).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20021111220 is a wasteful number, since it uses less digits than its factorization.

20021111220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33201 (or 33199 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 20021111220 its reverse (2211112002), we get a palindrome (22232223222).

The spelling of 20021111220 in words is "twenty billion, twenty-one million, one hundred eleven thousand, two hundred twenty".