20500728 has 32 divisors (see below), whose sum is σ = 53481600. Its totient is φ = 6536288.

The previous prime is 20500717. The next prime is 20500741. The reversal of 20500728 is 82700502.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a junction number, because it is equal to n+sod(n) for n = 20500698 and 20500707.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18018 + ... + 19121.

It is an arithmetic number, because the mean of its divisors is an integer number (1671300).

Almost surely, 2^20500728 is an apocalyptic number.

It is an amenable number.

20500728 is an abundant number, since it is smaller than the sum of its proper divisors (32980872).

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

20500728 is a wasteful number, since it uses less digits than its factorization.

20500728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37171 (or 37167 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 24.

The square root of 20500728 is about 4527.7729625060. The cubic root of 20500728 is about 273.6884234221.

The spelling of 20500728 in words is "twenty million, five hundred thousand, seven hundred twenty-eight".