1111021020 has 72 divisors (see below), whose sum is σ = 3377569104. Its totient is φ = 295615488.

The previous prime is 1111020983. The next prime is 1111021099. The reversal of 1111021020 is 201201111.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 1111020993 and 1111021011.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 77452 + ... + 90668.

It is an arithmetic number, because the mean of its divisors is an integer number (46910682).

Almost surely, 2^1111021020 is an apocalyptic number.

1111021020 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 1111021020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1688784552).

1111021020 is an abundant number, since it is smaller than the sum of its proper divisors (2266548084).

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

1111021020 is a wasteful number, since it uses less digits than its factorization.

1111021020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13699 (or 13694 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

The square root of 1111021020 is about 33331.9819392727. The cubic root of 1111021020 is about 1035.7161744918.

Adding to 1111021020 its reverse (201201111), we get a palindrome (1312222131).

The spelling of 1111021020 in words is "one billion, one hundred eleven million, twenty-one thousand, twenty".