20828320 has 48 divisors (see below), whose sum is σ = 49480200. Its totient is φ = 8285184.

The previous prime is 20828309. The next prime is 20828323. The reversal of 20828320 is 2382802.

It can be written as a sum of positive squares in 4 ways, for example, as 18766224 + 2062096 = 4332^2 + 1436^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20828323) by changing a digit.

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, 55654 + ... + 56026.

Almost surely, 2^20828320 is an apocalyptic number.

20828320 is a gapful number since it is divisible by the number (20) 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 20828320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24740100).

20828320 is an abundant number, since it is smaller than the sum of its proper divisors (28651880).

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

20828320 is a wasteful number, since it uses less digits than its factorization.

20828320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 737 (or 729 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 25.

The square root of 20828320 is about 4563.8054296826. The cubic root of 20828320 is about 275.1385307546.

The spelling of 20828320 in words is "twenty million, eight hundred twenty-eight thousand, three hundred twenty".