18263881 has 8 divisors (see below), whose sum is σ = 19035720. Its totient is φ = 17501568.

The previous prime is 18263879. The next prime is 18263887. The reversal of 18263881 is 18836281.

It can be written as a sum of positive squares in 4 ways, for example, as 665856 + 17598025 = 816^2 + 4195^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18263881 - 2¹ = 18263879 is a prime.

It is a super-2 number, since 2×18263881² = 667138698364322, 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 18263881.

It is not an unprimeable number, because it can be changed into a prime (18263887) 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 in 7 ways as a sum of consecutive naturals, for example, 1675 + ... + 6271.

It is an arithmetic number, because the mean of its divisors is an integer number (2379465).

Almost surely, 2^18263881 is an apocalyptic number.

It is an amenable number.

18263881 is a deficient number, since it is larger than the sum of its proper divisors (771839).

18263881 is a wasteful number, since it uses less digits than its factorization.

18263881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4763.

The product of its digits is 18432, while the sum is 37.

The square root of 18263881 is about 4273.6262120125. The cubic root of 18263881 is about 263.3486054630.

The spelling of 18263881 in words is "eighteen million, two hundred sixty-three thousand, eight hundred eighty-one".