809497728 has 192 divisors, whose sum is σ = 2530644480. Its totient is φ = 246896640.

The previous prime is 809497723. The next prime is 809497739. The reversal of 809497728 is 827794908.

809497728 is a `hidden beast` number, since 80 + 9 + 497 + 72 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (192).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (809497723) 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, 2860275 + ... + 2860557.

It is an arithmetic number, because the mean of its divisors is an integer number (13180440).

Almost surely, 2^809497728 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 809497728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1265322240).

809497728 is an abundant number, since it is smaller than the sum of its proper divisors (1721146752).

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

809497728 is a wasteful number, since it uses less digits than its factorization.

809497728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 507 (or 492 counting only the distinct ones).

The product of its (nonzero) digits is 2032128, while the sum is 54.

The square root of 809497728 is about 28451.6735535891. The cubic root of 809497728 is about 931.9770359118.

The spelling of 809497728 in words is "eight hundred nine million, four hundred ninety-seven thousand, seven hundred twenty-eight".