809639040 has 256 divisors, whose sum is σ = 2982251520. Its totient is φ = 183005184.

The previous prime is 809639009. The next prime is 809639063. The reversal of 809639040 is 40936908.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 809639040.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1437799 + ... + 1438361.

It is an arithmetic number, because the mean of its divisors is an integer number (11649420).

Almost surely, 2^809639040 is an apocalyptic number.

809639040 is a gapful number since it is divisible by the number (80) 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 809639040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1491125760).

809639040 is an abundant number, since it is smaller than the sum of its proper divisors (2172612480).

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

809639040 is a wasteful number, since it uses less digits than its factorization.

809639040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 699 (or 687 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 39.

The square root of 809639040 is about 28454.1568140755. The cubic root of 809639040 is about 932.0312637256.

The spelling of 809639040 in words is "eight hundred nine million, six hundred thirty-nine thousand, forty".