18243889 has 4 divisors (see below), whose sum is σ = 18375280. Its totient is φ = 18112500.

The previous prime is 18243881. The next prime is 18243913. The reversal of 18243889 is 98834281.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18243889 - 2³ = 18243881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18243881) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65487 + ... + 65764.

It is an arithmetic number, because the mean of its divisors is an integer number (4593820).

Almost surely, 2^18243889 is an apocalyptic number.

It is an amenable number.

18243889 is a deficient number, since it is larger than the sum of its proper divisors (131391).

18243889 is a wasteful number, since it uses less digits than its factorization.

18243889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131390.

The product of its digits is 110592, while the sum is 43.

The square root of 18243889 is about 4271.2865743239. The cubic root of 18243889 is about 263.2524815432.

The spelling of 18243889 in words is "eighteen million, two hundred forty-three thousand, eight hundred eighty-nine".