1118099981 has 2 divisors, whose sum is σ = 1118099982. Its totient is φ = 1118099980.

The previous prime is 1118099947. The next prime is 1118099987. The reversal of 1118099981 is 1899908111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 915607081 + 202492900 = 30259^2 + 14230^2 .

It is an emirp because it is prime and its reverse (1899908111) is a distict prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 1866608111 and 1118066681.

It is a cyclic number.

It is not a de Polignac number, because 1118099981 - 2³⁰ = 44358157 is a prime.

It is a super-2 number, since 2×1118099981² = 2500295135024400722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1118099987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 559049990 + 559049991.

It is an arithmetic number, because the mean of its divisors is an integer number (559049991).

Almost surely, 2^1118099981 is an apocalyptic number.

It is an amenable number.

1118099981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1118099981 is an equidigital number, since it uses as much as digits as its factorization.

1118099981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 46656, while the sum is 47.

The square root of 1118099981 is about 33438.0020485674. The cubic root of 1118099981 is about 1037.9112357472.

The spelling of 1118099981 in words is "one billion, one hundred eighteen million, ninety-nine thousand, nine hundred eighty-one".