1220111220 has 96 divisors (see below), whose sum is σ = 3631380480. Its totient is φ = 305216640.

The previous prime is 1220111219. The next prime is 1220111231. The reversal of 1220111220 is 221110221.

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 = 1220111196 and 1220111205.

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, 112225 + ... + 122615.

It is an arithmetic number, because the mean of its divisors is an integer number (37826880).

Almost surely, 2^1220111220 is an apocalyptic number.

1220111220 is a gapful number since it is divisible by the number (10) 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 1220111220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1815690240).

1220111220 is an abundant number, since it is smaller than the sum of its proper divisors (2411269260).

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

1220111220 is a wasteful number, since it uses less digits than its factorization.

1220111220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10525 (or 10523 counting only the distinct ones).

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

The square root of 1220111220 is about 34930.0904665304. The cubic root of 1220111220 is about 1068.5621996203.

Adding to 1220111220 its reverse (221110221), we get a palindrome (1441221441).

Subtracting from 1220111220 its reverse (221110221), we obtain a palindrome (999000999).

The spelling of 1220111220 in words is "one billion, two hundred twenty million, one hundred eleven thousand, two hundred twenty".