1115815820 has 96 divisors (see below), whose sum is σ = 2756073600. Its totient is φ = 371496960.

The previous prime is 1115815807. The next prime is 1115815823. The reversal of 1115815820 is 285185111.

It is not an unprimeable number, because it can be changed into a prime (1115815823) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2002982 + ... + 2003538.

It is an arithmetic number, because the mean of its divisors is an integer number (28709100).

Almost surely, 2^1115815820 is an apocalyptic number.

1115815820 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 1115815820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1378036800).

1115815820 is an abundant number, since it is smaller than the sum of its proper divisors (1640257780).

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

1115815820 is a wasteful number, since it uses less digits than its factorization.

1115815820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 963 (or 961 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 32.

The square root of 1115815820 is about 33403.8294211906. The cubic root of 1115815820 is about 1037.2039726391.

The spelling of 1115815820 in words is "one billion, one hundred fifteen million, eight hundred fifteen thousand, eight hundred twenty".