1118981 has 4 divisors (see below), whose sum is σ = 1121100. Its totient is φ = 1116864.

The previous prime is 1118969. The next prime is 1118987. The reversal of 1118981 is 1898111.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1898111 = 149 ⋅12739.

It can be written as a sum of positive squares in 2 ways, for example, as 136900 + 982081 = 370^2 + 991^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1118981 is a prime.

It is a super-2 number, since 2×1118981² = 2504236956722, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1118987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 455 + ... + 1563.

It is an arithmetic number, because the mean of its divisors is an integer number (280275).

2^1118981 is an apocalyptic number.

It is an amenable number.

1118981 is a deficient number, since it is larger than the sum of its proper divisors (2119).

1118981 is a wasteful number, since it uses less digits than its factorization.

1118981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2118.

The product of its digits is 576, while the sum is 29.

The square root of 1118981 is about 1057.8189826242. The cubic root of 1118981 is about 103.8183775313.

The spelling of 1118981 in words is "one million, one hundred eighteen thousand, nine hundred eighty-one".