20997328 has 40 divisors (see below), whose sum is σ = 45238176. Its totient is φ = 9360000.

The previous prime is 20997313. The next prime is 20997349. The reversal of 20997328 is 82379902.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8203 + ... + 10453.

Almost surely, 2^20997328 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 20997328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22619088).

20997328 is an abundant number, since it is smaller than the sum of its proper divisors (24240848).

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

20997328 is a wasteful number, since it uses less digits than its factorization.

20997328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2323 (or 2317 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 40.

The square root of 20997328 is about 4582.2841465802. The cubic root of 20997328 is about 275.8807157999.

The spelling of 20997328 in words is "twenty million, nine hundred ninety-seven thousand, three hundred twenty-eight".