20475728 has 100 divisors (see below), whose sum is σ = 51056628. Its totient is φ = 7902720.

The previous prime is 20475709. The next prime is 20475731. The reversal of 20475728 is 82757402.

It can be written as a sum of positive squares in 2 ways, for example, as 1882384 + 18593344 = 1372^2 + 4312^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 499388 + ... + 499428.

Almost surely, 2^20475728 is an apocalyptic number.

20475728 is a gapful number since it is divisible by the number (28) 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 20475728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25528314).

20475728 is an abundant number, since it is smaller than the sum of its proper divisors (30580900).

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

20475728 is an equidigital number, since it uses as much as digits as its factorization.

20475728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90 (or 63 counting only the distinct ones).

The product of its (nonzero) digits is 31360, while the sum is 35.

The square root of 20475728 is about 4525.0113812012. The cubic root of 20475728 is about 273.5771266630.

The spelling of 20475728 in words is "twenty million, four hundred seventy-five thousand, seven hundred twenty-eight".