1115021220 has 48 divisors (see below), whose sum is σ = 3123973440. Its totient is φ = 297156736.

The previous prime is 1115021197. The next prime is 1115021221. The reversal of 1115021220 is 221205111.

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 1115021220.

It is not an unprimeable number, because it can be changed into a prime (1115021221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 113671 + ... + 123089.

It is an arithmetic number, because the mean of its divisors is an integer number (65082780).

Almost surely, 2^1115021220 is an apocalyptic number.

1115021220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1115021220 is an abundant number, since it is smaller than the sum of its proper divisors (2008952220).

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

1115021220 is a wasteful number, since it uses less digits than its factorization.

1115021220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11404 (or 11402 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 15.

The square root of 1115021220 is about 33391.9334570492. The cubic root of 1115021220 is about 1036.9577079854.

Adding to 1115021220 its reverse (221205111), we get a palindrome (1336226331).

The spelling of 1115021220 in words is "one billion, one hundred fifteen million, twenty-one thousand, two hundred twenty".