1115809020 has 240 divisors, whose sum is σ = 3622449600. Its totient is φ = 287400960.

The previous prime is 1115809007. The next prime is 1115809027. The reversal of 1115809020 is 209085111.

It is a super-2 number, since 2×1115809020² = 2490059538226720800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1115809027) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 10236726 + ... + 10236834.

It is an arithmetic number, because the mean of its divisors is an integer number (15093540).

Almost surely, 2^1115809020 is an apocalyptic number.

1115809020 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 1115809020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1811224800).

1115809020 is an abundant number, since it is smaller than the sum of its proper divisors (2506640580).

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

1115809020 is a wasteful number, since it uses less digits than its factorization.

1115809020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 290 (or 279 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 27.

The square root of 1115809020 is about 33403.7276362983. The cubic root of 1115809020 is about 1037.2018656602.

The spelling of 1115809020 in words is "one billion, one hundred fifteen million, eight hundred nine thousand, twenty".