19887984 has 80 divisors (see below), whose sum is σ = 60115200. Its totient is φ = 6277824.

The previous prime is 19887979. The next prime is 19888021. The reversal of 19887984 is 48978891.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 19887984.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6997 + ... + 9419.

It is an arithmetic number, because the mean of its divisors is an integer number (751440).

Almost surely, 2^19887984 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 19887984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30057600).

19887984 is an abundant number, since it is smaller than the sum of its proper divisors (40227216).

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

19887984 is a wasteful number, since it uses less digits than its factorization.

19887984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2459 (or 2447 counting only the distinct ones).

The product of its digits is 1161216, while the sum is 54.

The square root of 19887984 is about 4459.5946004093. The cubic root of 19887984 is about 270.9340489377.

The spelling of 19887984 in words is "nineteen million, eight hundred eighty-seven thousand, nine hundred eighty-four".