20111312220 has 96 divisors (see below), whose sum is σ = 57553929216. Its totient is φ = 5244883200.

The previous prime is 20111312219. The next prime is 20111312237. The reversal of 20111312220 is 2221311102.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 20111312220.

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, 6035955 + ... + 6039285.

It is an arithmetic number, because the mean of its divisors is an integer number (599520096).

Almost surely, 2^20111312220 is an apocalyptic number.

20111312220 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 20111312220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28776964608).

20111312220 is an abundant number, since it is smaller than the sum of its proper divisors (37442616996).

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

20111312220 is a wasteful number, since it uses less digits than its factorization.

20111312220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5531 (or 5529 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 20111312220 its reverse (2221311102), we get a palindrome (22332623322).

The spelling of 20111312220 in words is "twenty billion, one hundred eleven million, three hundred twelve thousand, two hundred twenty".