809925440640 has 512 divisors, whose sum is σ = 2708181665280. Its totient is φ = 205701120000.

The previous prime is 809925440629. The next prime is 809925440647. The reversal of 809925440640 is 46044529908.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (809925440647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 725089362 + ... + 725090478.

It is an arithmetic number, because the mean of its divisors is an integer number (5289417315).

Almost surely, 2^809925440640 is an apocalyptic number.

809925440640 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 809925440640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1354090832640).

809925440640 is an abundant number, since it is smaller than the sum of its proper divisors (1898256224640).

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

809925440640 is a wasteful number, since it uses less digits than its factorization.

809925440640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1392 (or 1380 counting only the distinct ones).

The product of its (nonzero) digits is 2488320, while the sum is 51.

The spelling of 809925440640 in words is "eight hundred nine billion, nine hundred twenty-five million, four hundred forty thousand, six hundred forty".