20872728 has 64 divisors (see below), whose sum is σ = 58744800. Its totient is φ = 6951744.

The previous prime is 20872727. The next prime is 20872763. The reversal of 20872728 is 82727802.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 20872692 and 20872701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20872727) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16900 + ... + 18092.

Almost surely, 2^20872728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20872728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29372400).

20872728 is an abundant number, since it is smaller than the sum of its proper divisors (37872072).

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

20872728 is an equidigital number, since it uses as much as digits as its factorization.

20872728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1220 (or 1198 counting only the distinct ones).

The product of its (nonzero) digits is 25088, while the sum is 36.

The square root of 20872728 is about 4568.6680772409. The cubic root of 20872728 is about 275.3339326333. Note that the first 3 decimals are identical.

The spelling of 20872728 in words is "twenty million, eight hundred seventy-two thousand, seven hundred twenty-eight".