111221020 has 12 divisors (see below), whose sum is σ = 233564184. Its totient is φ = 44488400.

The previous prime is 111220999. The next prime is 111221023. The reversal of 111221020 is 20122111.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 111220988 and 111221006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111221023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2780506 + ... + 2780545.

It is an arithmetic number, because the mean of its divisors is an integer number (19463682).

Almost surely, 2^111221020 is an apocalyptic number.

111221020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

111221020 is an abundant number, since it is smaller than the sum of its proper divisors (122343164).

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

111221020 is a wasteful number, since it uses less digits than its factorization.

111221020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5561060 (or 5561058 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 111221020 is about 10546.1376816349. The cubic root of 111221020 is about 480.9083205786.

Adding to 111221020 its reverse (20122111), we get a palindrome (131343131).

The spelling of 111221020 in words is "one hundred eleven million, two hundred twenty-one thousand, twenty".