20728316 has 48 divisors (see below), whose sum is σ = 44620800. Its totient is φ = 8227008.

The previous prime is 20728291. The next prime is 20728339. The reversal of 20728316 is 61382702.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24590 + ... + 25418.

It is an arithmetic number, because the mean of its divisors is an integer number (929600).

Almost surely, 2^20728316 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 20728316, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22310400).

20728316 is an abundant number, since it is smaller than the sum of its proper divisors (23892484).

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

20728316 is a wasteful number, since it uses less digits than its factorization.

20728316 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 906 (or 904 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 20728316 is about 4552.8360392178. The cubic root of 20728316 is about 274.6974788959.

The spelling of 20728316 in words is "twenty million, seven hundred twenty-eight thousand, three hundred sixteen".