111111001220 has 48 divisors (see below), whose sum is σ = 239412641328. Its totient is φ = 43289917440.

The previous prime is 111111001217. The next prime is 111111001249. The reversal of 111111001220 is 22100111111.

It can be written as a sum of positive squares in 8 ways, for example, as 68165899396 + 42945101824 = 261086^2 + 207232^2 .

It is a super-2 number, since 2×111111001220² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 396134 + ... + 615746.

It is an arithmetic number, because the mean of its divisors is an integer number (4987763361).

Almost surely, 2^111111001220 is an apocalyptic number.

111111001220 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 111111001220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119706320664).

111111001220 is an abundant number, since it is smaller than the sum of its proper divisors (128301640108).

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

111111001220 is a wasteful number, since it uses less digits than its factorization.

111111001220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220280 (or 220278 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 111111001220 its reverse (22100111111), we get a palindrome (133211112331).

The spelling of 111111001220 in words is "one hundred eleven billion, one hundred eleven million, one thousand, two hundred twenty".