1155221115 has 32 divisors (see below), whose sum is σ = 1932719616. Its totient is φ = 588107520.

The previous prime is 1155221099. The next prime is 1155221143. The reversal of 1155221115 is 5111225511.

It is not a de Polignac number, because 1155221115 - 2⁴ = 1155221099 is a prime.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 176532 + ... + 182958.

It is an arithmetic number, because the mean of its divisors is an integer number (60397488).

Almost surely, 2^1155221115 is an apocalyptic number.

1155221115 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1155221115 is a deficient number, since it is larger than the sum of its proper divisors (777498501).

1155221115 is a wasteful number, since it uses less digits than its factorization.

1155221115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6979.

The product of its digits is 500, while the sum is 24.

The square root of 1155221115 is about 33988.5438787836. The cubic root of 1155221115 is about 1049.2726981513.

Adding to 1155221115 its reverse (5111225511), we get a palindrome (6266446626).

The spelling of 1155221115 in words is "one billion, one hundred fifty-five million, two hundred twenty-one thousand, one hundred fifteen".