18361489 has 4 divisors (see below), whose sum is σ = 18371556. Its totient is φ = 18351424.

The previous prime is 18361487. The next prime is 18361493. The reversal of 18361489 is 98416381.

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.

It can be written as a sum of positive squares in 2 ways, for example, as 4730625 + 13630864 = 2175^2 + 3692^2 .

It is a cyclic number.

It is not a de Polignac number, because 18361489 - 2¹ = 18361487 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18361487) 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, 1444 + ... + 6229.

It is an arithmetic number, because the mean of its divisors is an integer number (4592889).

Almost surely, 2^18361489 is an apocalyptic number.

It is an amenable number.

18361489 is a deficient number, since it is larger than the sum of its proper divisors (10067).

18361489 is an equidigital number, since it uses as much as digits as its factorization.

18361489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10066.

The product of its digits is 41472, while the sum is 40.

The square root of 18361489 is about 4285.0308050235. The cubic root of 18361489 is about 263.8169118136.

The spelling of 18361489 in words is "eighteen million, three hundred sixty-one thousand, four hundred eighty-nine".