1011111221220 has 192 divisors, whose sum is σ = 3111624875520. Its totient is φ = 244180099072.

The previous prime is 1011111221207. The next prime is 1011111221287. The reversal of 1011111221220 is 221221111101.

It is a happy number.

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 1011111221220.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 8608609 + ... + 8725271.

It is an arithmetic number, because the mean of its divisors is an integer number (16206379560).

Almost surely, 2^{1011111221220} is an apocalyptic number.

1011111221220 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 1011111221220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1555812437760).

1011111221220 is an abundant number, since it is smaller than the sum of its proper divisors (2100513654300).

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

1011111221220 is a wasteful number, since it uses less digits than its factorization.

1011111221220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117014 (or 117012 counting only the distinct ones).

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

Adding to 1011111221220 its reverse (221221111101), we get a palindrome (1232332332321).

The spelling of 1011111221220 in words is "one trillion, eleven billion, one hundred eleven million, two hundred twenty-one thousand, two hundred twenty".