18186489 has 6 divisors (see below), whose sum is σ = 26269386. Its totient is φ = 12124320.

The previous prime is 18186461. The next prime is 18186503. The reversal of 18186489 is 98468181.

It can be written as a sum of positive squares in only one way, i.e., 18020025 + 166464 = 4245^2 + 408^2 .

It is not a de Polignac number, because 18186489 - 2⁵ = 18186457 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18186089) 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 5 ways as a sum of consecutive naturals, for example, 1010352 + ... + 1010369.

It is an arithmetic number, because the mean of its divisors is an integer number (4378231).

Almost surely, 2^18186489 is an apocalyptic number.

It is an amenable number.

18186489 is a deficient number, since it is larger than the sum of its proper divisors (8082897).

18186489 is a wasteful number, since it uses less digits than its factorization.

18186489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2020727 (or 2020724 counting only the distinct ones).

The product of its digits is 110592, while the sum is 45.

The square root of 18186489 is about 4264.5619939215. The cubic root of 18186489 is about 262.9761046591.

The spelling of 18186489 in words is "eighteen million, one hundred eighty-six thousand, four hundred eighty-nine".