18112861 has 4 divisors (see below), whose sum is σ = 19506172. Its totient is φ = 16719552.

The previous prime is 18112817. The next prime is 18112879. The reversal of 18112861 is 16821181.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1425636 + 16687225 = 1194^2 + 4085^2 .

It is a cyclic number.

It is not a de Polignac number, because 18112861 - 2⁹ = 18112349 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18110861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 696636 + ... + 696661.

It is an arithmetic number, because the mean of its divisors is an integer number (4876543).

Almost surely, 2^18112861 is an apocalyptic number.

It is an amenable number.

18112861 is a deficient number, since it is larger than the sum of its proper divisors (1393311).

18112861 is a wasteful number, since it uses less digits than its factorization.

18112861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1393310.

The product of its digits is 768, while the sum is 28.

The square root of 18112861 is about 4255.9206994492. The cubic root of 18112861 is about 262.6207384103.

The spelling of 18112861 in words is "eighteen million, one hundred twelve thousand, eight hundred sixty-one".