20451328 has 26 divisors (see below), whose sum is σ = 40905854. Its totient is φ = 10223616.

The previous prime is 20451317. The next prime is 20451329. The reversal of 20451328 is 82315402.

It can be written as a sum of positive squares in only one way, i.e., 16257024 + 4194304 = 4032^2 + 2048^2 .

It is not an unprimeable number, because it can be changed into a prime (20451329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1600 + ... + 6592.

Almost surely, 2^20451328 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 20451328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20452927).

20451328 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

20451328 is an frugal number, since it uses more digits than its factorization.

20451328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5017 (or 4995 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 20451328 is about 4522.3144516940. The cubic root of 20451328 is about 273.4684136347.

The spelling of 20451328 in words is "twenty million, four hundred fifty-one thousand, three hundred twenty-eight".