20997584 has 60 divisors (see below), whose sum is σ = 45681600. Its totient is φ = 9321984.

The previous prime is 20997583. The next prime is 20997619. The reversal of 20997584 is 48579902.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20997583) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 87737 + ... + 87975.

It is an arithmetic number, because the mean of its divisors is an integer number (761360).

Almost surely, 2^20997584 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 20997584, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22840800).

20997584 is an abundant number, since it is smaller than the sum of its proper divisors (24684016).

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

20997584 is a wasteful number, since it uses less digits than its factorization.

20997584 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300 (or 277 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 44.

The square root of 20997584 is about 4582.3120801622. The cubic root of 20997584 is about 275.8818369771.

The spelling of 20997584 in words is "twenty million, nine hundred ninety-seven thousand, five hundred eighty-four".