20185728 has 32 divisors (see below), whose sum is σ = 53619360. Its totient is φ = 6728448.

The previous prime is 20185727. The next prime is 20185747. The reversal of 20185728 is 82758102.

It is a tau number, because it is divible by the number of its divisors (32).

It is a super-2 number, since 2×20185728² = 814927229779968, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20185723) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25900 + ... + 26667.

It is an arithmetic number, because the mean of its divisors is an integer number (1675605).

Almost surely, 2^20185728 is an apocalyptic number.

It is an amenable number.

20185728 is an abundant number, since it is smaller than the sum of its proper divisors (33433632).

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

20185728 is an equidigital number, since it uses as much as digits as its factorization.

20185728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52584 (or 52572 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 33.

The square root of 20185728 is about 4492.8529911405. The cubic root of 20185728 is about 272.2794129890.

The spelling of 20185728 in words is "twenty million, one hundred eighty-five thousand, seven hundred twenty-eight".