20478728 has 16 divisors (see below), whose sum is σ = 38525760. Its totient is φ = 10205200.

The previous prime is 20478719. The next prime is 20478739. The reversal of 20478728 is 82787402.

It is a junction number, because it is equal to n+sod(n) for n = 20478691 and 20478700.

It is an unprimeable number.

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, 1628 + ... + 6603.

It is an arithmetic number, because the mean of its divisors is an integer number (2407860).

Almost surely, 2^20478728 is an apocalyptic number.

It is an amenable number.

20478728 is a deficient number, since it is larger than the sum of its proper divisors (18047032).

20478728 is a wasteful number, since it uses less digits than its factorization.

20478728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8548 (or 8544 counting only the distinct ones).

The product of its (nonzero) digits is 50176, while the sum is 38.

The square root of 20478728 is about 4525.3428599389. The cubic root of 20478728 is about 273.5904870557.

The spelling of 20478728 in words is "twenty million, four hundred seventy-eight thousand, seven hundred twenty-eight".