19989216 has 144 divisors (see below), whose sum is σ = 64668240. Its totient is φ = 5806080.

The previous prime is 19989209. The next prime is 19989217. The reversal of 19989216 is 61298991.

It is a tau number, because it is divible by the number of its divisors (144).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19989217) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 70996 + ... + 71276.

It is an arithmetic number, because the mean of its divisors is an integer number (449085).

Almost surely, 2^19989216 is an apocalyptic number.

19989216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19989216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32334120).

19989216 is an abundant number, since it is smaller than the sum of its proper divisors (44679024).

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

19989216 is a wasteful number, since it uses less digits than its factorization.

19989216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 329 (or 318 counting only the distinct ones).

The product of its digits is 69984, while the sum is 45.

The square root of 19989216 is about 4470.9301045756. The cubic root of 19989216 is about 271.3929657556.

The spelling of 19989216 in words is "nineteen million, nine hundred eighty-nine thousand, two hundred sixteen".