18020863 has 4 divisors (see below), whose sum is σ = 20595280. Its totient is φ = 15446448.

The previous prime is 18020851. The next prime is 18020897. The reversal of 18020863 is 36802081.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 36802081 = 47 ⋅783023.

It is a cyclic number.

It is not a de Polignac number, because 18020863 - 2⁵ = 18020831 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 (18020263) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 1287198 + ... + 1287211.

It is an arithmetic number, because the mean of its divisors is an integer number (5148820).

Almost surely, 2^18020863 is an apocalyptic number.

18020863 is a deficient number, since it is larger than the sum of its proper divisors (2574417).

18020863 is an equidigital number, since it uses as much as digits as its factorization.

18020863 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2574416.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 18020863 is about 4245.0987032106. The cubic root of 18020863 is about 262.1753531559.

The spelling of 18020863 in words is "eighteen million, twenty thousand, eight hundred sixty-three".