20173728 has 24 divisors (see below), whose sum is σ = 52956288. Its totient is φ = 6724544.

The previous prime is 20173723. The next prime is 20173739. The reversal of 20173728 is 82737102.

It is a tau number, because it is divible by the number of its divisors (24).

It is a junction number, because it is equal to n+sod(n) for n = 20173695 and 20173704.

It is not an unprimeable number, because it can be changed into a prime (20173723) 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, 104976 + ... + 105167.

It is an arithmetic number, because the mean of its divisors is an integer number (2206512).

Almost surely, 2^20173728 is an apocalyptic number.

It is an amenable number.

20173728 is an abundant number, since it is smaller than the sum of its proper divisors (32782560).

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

20173728 is a wasteful number, since it uses less digits than its factorization.

20173728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210156 (or 210148 counting only the distinct ones).

The product of its (nonzero) digits is 4704, while the sum is 30.

The square root of 20173728 is about 4491.5173382722. The cubic root of 20173728 is about 272.2254474574.

The spelling of 20173728 in words is "twenty million, one hundred seventy-three thousand, seven hundred twenty-eight".