20728512 has 168 divisors, whose sum is σ = 69896736. Its totient is φ = 5750784.

The previous prime is 20728501. The next prime is 20728517. The reversal of 20728512 is 21582702.

It is a tau number, because it is divible by the number of its divisors (168).

It is not an unprimeable number, because it can be changed into a prime (20728517) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 213648 + ... + 213744.

It is an arithmetic number, because the mean of its divisors is an integer number (416052).

Almost surely, 2^20728512 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 20728512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34948368).

20728512 is an abundant number, since it is smaller than the sum of its proper divisors (49168224).

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

20728512 is a wasteful number, since it uses less digits than its factorization.

20728512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175 (or 162 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 20728512 is about 4552.8575642117. The cubic root of 20728512 is about 274.6983447088.

The spelling of 20728512 in words is "twenty million, seven hundred twenty-eight thousand, five hundred twelve".