20481728 has 14 divisors (see below), whose sum is σ = 40643556. Its totient is φ = 10240832.

The previous prime is 20481709. The next prime is 20481733. The reversal of 20481728 is 82718402.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 20481694 and 20481703.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159950 + ... + 160077.

Almost surely, 2^20481728 is an apocalyptic number.

It is an amenable number.

20481728 is a deficient number, since it is larger than the sum of its proper divisors (20161828).

20481728 is an equidigital number, since it uses as much as digits as its factorization.

20481728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320039 (or 320029 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 32.

The square root of 20481728 is about 4525.6743143978. The cubic root of 20481728 is about 273.6038461436.

The spelling of 20481728 in words is "twenty million, four hundred eighty-one thousand, seven hundred twenty-eight".