18489984 has 64 divisors (see below), whose sum is σ = 49572000. Its totient is φ = 6106112.

The previous prime is 18489971. The next prime is 18490001. The reversal of 18489984 is 48998481.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68602 + ... + 68870.

Almost surely, 2^18489984 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18489984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24786000).

18489984 is an abundant number, since it is smaller than the sum of its proper divisors (31082016).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18489984 is a wasteful number, since it uses less digits than its factorization.

18489984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 465 (or 453 counting only the distinct ones).

The product of its digits is 663552, while the sum is 51.

The square root of 18489984 is about 4299.9981395345. The cubic root of 18489984 is about 264.4308849662.

The spelling of 18489984 in words is "eighteen million, four hundred eighty-nine thousand, nine hundred eighty-four".