20820384 has 144 divisors (see below), whose sum is σ = 65493792. Its totient is φ = 6234624.

The previous prime is 20820383. The next prime is 20820407. The reversal of 20820384 is 48302802.

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

It is not an unprimeable number, because it can be changed into a prime (20820383) 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, 250807 + ... + 250889.

It is an arithmetic number, because the mean of its divisors is an integer number (454818).

Almost surely, 2^20820384 is an apocalyptic number.

20820384 is a gapful number since it is divisible by the number (24) 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 20820384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32746896).

20820384 is an abundant number, since it is smaller than the sum of its proper divisors (44673408).

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

20820384 is a wasteful number, since it uses less digits than its factorization.

20820384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179 (or 168 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 20820384 is about 4562.9358969856. The cubic root of 20820384 is about 275.1035819164.

The spelling of 20820384 in words is "twenty million, eight hundred twenty thousand, three hundred eighty-four".