18668849 has 4 divisors (see below), whose sum is σ = 19651440. Its totient is φ = 17686260.

The previous prime is 18668833. The next prime is 18668857. The reversal of 18668849 is 94886681.

It is a happy number.

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 18668849 - 2⁴ = 18668833 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18668797 and 18668806.

It is not an unprimeable number, because it can be changed into a prime (18668809) 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 3 ways as a sum of consecutive naturals, for example, 491267 + ... + 491304.

It is an arithmetic number, because the mean of its divisors is an integer number (4912860).

Almost surely, 2^18668849 is an apocalyptic number.

18668849 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

18668849 is a deficient number, since it is larger than the sum of its proper divisors (982591).

18668849 is an equidigital number, since it uses as much as digits as its factorization.

18668849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 982590.

The product of its digits is 663552, while the sum is 50.

The square root of 18668849 is about 4320.7463475654. The cubic root of 18668849 is about 265.2808177774.

The spelling of 18668849 in words is "eighteen million, six hundred sixty-eight thousand, eight hundred forty-nine".