20489728 has 40 divisors (see below), whose sum is σ = 46796112. Its totient is φ = 8779776.

The previous prime is 20489723. The next prime is 20489737. The reversal of 20489728 is 82798402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20489723) 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, 726 + ... + 6442.

Almost surely, 2^20489728 is an apocalyptic number.

20489728 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20489728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23398056).

20489728 is an abundant number, since it is smaller than the sum of its proper divisors (26306384).

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

20489728 is an frugal number, since it uses more digits than its factorization.

20489728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5742 (or 5726 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 40.

The square root of 20489728 is about 4526.5580742988. The cubic root of 20489728 is about 273.6394640018.

The spelling of 20489728 in words is "twenty million, four hundred eighty-nine thousand, seven hundred twenty-eight".