20147728 has 20 divisors (see below), whose sum is σ = 39989628. Its totient is φ = 9827840.

The previous prime is 20147723. The next prime is 20147761. The reversal of 20147728 is 82774102.

It can be written as a sum of positive squares in 2 ways, for example, as 9072144 + 11075584 = 3012^2 + 3328^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20147728.

It is not an unprimeable number, because it can be changed into a prime (20147723) 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 3 ways as a sum of consecutive naturals, for example, 14701 + ... + 16012.

Almost surely, 2^20147728 is an apocalyptic number.

It is an amenable number.

20147728 is a deficient number, since it is larger than the sum of its proper divisors (19841900).

20147728 is a wasteful number, since it uses less digits than its factorization.

20147728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30762 (or 30756 counting only the distinct ones).

The product of its (nonzero) digits is 6272, while the sum is 31.

The square root of 20147728 is about 4488.6220602764. The cubic root of 20147728 is about 272.1084486810.

The spelling of 20147728 in words is "twenty million, one hundred forty-seven thousand, seven hundred twenty-eight".