20801584 has 40 divisors (see below), whose sum is σ = 42140160. Its totient is φ = 9934848.

The previous prime is 20801579. The next prime is 20801593. The reversal of 20801584 is 48510802.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 58752 + ... + 59104.

It is an arithmetic number, because the mean of its divisors is an integer number (1053504).

Almost surely, 2^20801584 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 20801584, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21070080).

20801584 is an abundant number, since it is smaller than the sum of its proper divisors (21338576).

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

20801584 is a wasteful number, since it uses less digits than its factorization.

20801584 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 517 (or 511 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 28.

The square root of 20801584 is about 4560.8753545783. The cubic root of 20801584 is about 275.0207543565.

The spelling of 20801584 in words is "twenty million, eight hundred one thousand, five hundred eighty-four".