18919824 has 80 divisors (see below), whose sum is σ = 60948480. Its totient is φ = 4913280.

The previous prime is 18919811. The next prime is 18919841. The reversal of 18919824 is 42891981.

It is a Harshad number since it is a multiple of its sum of digits (42).

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, 1137 + ... + 6255.

It is an arithmetic number, because the mean of its divisors is an integer number (761856).

Almost surely, 2^18919824 is an apocalyptic number.

18919824 is a gapful number since it is divisible by the number (14) 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 18919824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30474240).

18919824 is an abundant number, since it is smaller than the sum of its proper divisors (42028656).

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

18919824 is a wasteful number, since it uses less digits than its factorization.

18919824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5148 (or 5142 counting only the distinct ones).

The product of its digits is 41472, while the sum is 42.

The square root of 18919824 is about 4349.6924029177. The cubic root of 18919824 is about 266.4642992445.

The spelling of 18919824 in words is "eighteen million, nine hundred nineteen thousand, eight hundred twenty-four".