1011112121220 has 96 divisors (see below), whose sum is σ = 2882368419840. Its totient is φ = 264758901120.

The previous prime is 1011112121219. The next prime is 1011112121221. The reversal of 1011112121220 is 221212111101.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1011112121219) and next prime (1011112121221).

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 1011112121220.

It is not an unprimeable number, because it can be changed into a prime (1011112121221) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2964085 + ... + 3287555.

It is an arithmetic number, because the mean of its divisors is an integer number (30024671040).

Almost surely, 2^{1011112121220} is an apocalyptic number.

1011112121220 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 1011112121220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1441184209920).

1011112121220 is an abundant number, since it is smaller than the sum of its proper divisors (1871256298620).

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

1011112121220 is a wasteful number, since it uses less digits than its factorization.

1011112121220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 324425 (or 324423 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 1011112121220 its reverse (221212111101), we get a palindrome (1232324232321).

The spelling of 1011112121220 in words is "one trillion, eleven billion, one hundred twelve million, one hundred twenty-one thousand, two hundred twenty".