20320256 has 78 divisors (see below), whose sum is σ = 45754926. Its totient is φ = 9011200.

The previous prime is 20320241. The next prime is 20320277. The reversal of 20320256 is 65202302.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 12390400 + 7929856 = 3520^2 + 2816^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 495596 + ... + 495636.

Almost surely, 2^20320256 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 20320256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22877463).

20320256 is an abundant number, since it is smaller than the sum of its proper divisors (25434670).

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

20320256 is an equidigital number, since it uses as much as digits as its factorization.

20320256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87 (or 54 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 20.

The square root of 20320256 is about 4507.7994631527. The cubic root of 20320256 is about 272.8829439080.

Adding to 20320256 its reverse (65202302), we get a palindrome (85522558).

The spelling of 20320256 in words is "twenty million, three hundred twenty thousand, two hundred fifty-six".