1111121020 has 48 divisors (see below), whose sum is σ = 2484548640. Its totient is φ = 415944704.

The previous prime is 1111120957. The next prime is 1111121021. The reversal of 1111121020 is 201211111.

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 = 1111120988 and 1111121006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1111121021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 51732 + ... + 69988.

It is an arithmetic number, because the mean of its divisors is an integer number (51761430).

Almost surely, 2^1111121020 is an apocalyptic number.

1111121020 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 1111121020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1242274320).

1111121020 is an abundant number, since it is smaller than the sum of its proper divisors (1373427620).

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

1111121020 is a wasteful number, since it uses less digits than its factorization.

1111121020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18462 (or 18460 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 10.

The square root of 1111121020 is about 33333.4819663353. The cubic root of 1111121020 is about 1035.7472475643.

Adding to 1111121020 its reverse (201211111), we get a palindrome (1312332131).

Subtracting from 1111121020 its reverse (201211111), we obtain a palindrome (909909909).

It can be divided in two parts, 11111 and 21020, that added together give a triangular number (32131 = T₂₅₃).

The spelling of 1111121020 in words is "one billion, one hundred eleven million, one hundred twenty-one thousand, twenty".