1118817181 has 4 divisors (see below), whose sum is σ = 1128718332. Its totient is φ = 1108916032.

The previous prime is 1118817173. The next prime is 1118817191. The reversal of 1118817181 is 1817188111.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1817188111 = 29 ⋅62661659.

It can be written as a sum of positive squares in 2 ways, for example, as 612117081 + 506700100 = 24741^2 + 22510^2 .

It is a cyclic number.

It is not a de Polignac number, because 1118817181 - 2³ = 1118817173 is a prime.

It is a super-2 number, since 2×1118817181² = 2503503769001573522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1118817181.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1118817101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4950406 + ... + 4950631.

It is an arithmetic number, because the mean of its divisors is an integer number (282179583).

Almost surely, 2^1118817181 is an apocalyptic number.

It is an amenable number.

1118817181 is a deficient number, since it is larger than the sum of its proper divisors (9901151).

1118817181 is an equidigital number, since it uses as much as digits as its factorization.

1118817181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9901150.

The product of its digits is 3584, while the sum is 37.

The square root of 1118817181 is about 33448.7246543123. The cubic root of 1118817181 is about 1038.1331094156.

The spelling of 1118817181 in words is "one billion, one hundred eighteen million, eight hundred seventeen thousand, one hundred eighty-one".