1155603220 has 48 divisors (see below), whose sum is σ = 2588377680. Its totient is φ = 431857664.

The previous prime is 1155603209. The next prime is 1155603259. The reversal of 1155603220 is 223065511.

It can be written as a sum of positive squares in 8 ways, for example, as 124679556 + 1030923664 = 11166^2 + 32108^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34176 + ... + 58984.

It is an arithmetic number, because the mean of its divisors is an integer number (53924535).

Almost surely, 2^1155603220 is an apocalyptic number.

1155603220 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 1155603220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1294188840).

1155603220 is an abundant number, since it is smaller than the sum of its proper divisors (1432774460).

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

1155603220 is a wasteful number, since it uses less digits than its factorization.

1155603220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24972 (or 24970 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 1155603220 is about 33994.1644992196. The cubic root of 1155603220 is about 1049.3883724416.

Adding to 1155603220 its reverse (223065511), we get a palindrome (1378668731).

The spelling of 1155603220 in words is "one billion, one hundred fifty-five million, six hundred three thousand, two hundred twenty".