18821489 has 8 divisors (see below), whose sum is σ = 19224960. Its totient is φ = 18421200.

The previous prime is 18821459. The next prime is 18821497. The reversal of 18821489 is 98412881.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18821489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18821449) 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, 13934 + ... + 15224.

It is an arithmetic number, because the mean of its divisors is an integer number (2403120).

Almost surely, 2^18821489 is an apocalyptic number.

It is an amenable number.

18821489 is a deficient number, since it is larger than the sum of its proper divisors (403471).

18821489 is a wasteful number, since it uses less digits than its factorization.

18821489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1591.

The product of its digits is 36864, while the sum is 41.

The square root of 18821489 is about 4338.3740041633. The cubic root of 18821489 is about 266.0018514202.

The spelling of 18821489 in words is "eighteen million, eight hundred twenty-one thousand, four hundred eighty-nine".