19985904 has 60 divisors (see below), whose sum is σ = 57142176. Its totient is φ = 6518016.

The previous prime is 19985869. The next prime is 19985909. The reversal of 19985904 is 40958991.

It is a self number, because there is not a number n which added to its sum of digits gives 19985904.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19985909) 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 11 ways as a sum of consecutive naturals, for example, 5292 + ... + 8244.

Almost surely, 2^19985904 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 19985904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28571088).

19985904 is an abundant number, since it is smaller than the sum of its proper divisors (37156272).

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

19985904 is a wasteful number, since it uses less digits than its factorization.

19985904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3014 (or 3005 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 45.

The square root of 19985904 is about 4470.5596965033. The cubic root of 19985904 is about 271.3779759539.

The spelling of 19985904 in words is "nineteen million, nine hundred eighty-five thousand, nine hundred four".