809591505218 has 16 divisors (see below), whose sum is σ = 1290029928000. Its totient is φ = 379972447632.

The previous prime is 809591505133. The next prime is 809591505227. The reversal of 809591505218 is 812505195908.

It is a super-2 number, since 2×809591505218² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 809591505218.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 97725398 + ... + 97733681.

It is an arithmetic number, because the mean of its divisors is an integer number (80626870500).

Almost surely, 2^809591505218 is an apocalyptic number.

809591505218 is a deficient number, since it is larger than the sum of its proper divisors (480438422782).

809591505218 is a wasteful number, since it uses less digits than its factorization.

809591505218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195459209.

The product of its (nonzero) digits is 1296000, while the sum is 53.

The spelling of 809591505218 in words is "eight hundred nine billion, five hundred ninety-one million, five hundred five thousand, two hundred eighteen".