809971621536 has 192 divisors, whose sum is σ = 2790333342720. Its totient is φ = 199309455360.

The previous prime is 809971621519. The next prime is 809971621541. The reversal of 809971621536 is 635126179908.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 2743081 + ... + 3023976.

It is an arithmetic number, because the mean of its divisors is an integer number (14532986160).

Almost surely, 2^809971621536 is an apocalyptic number.

It is an amenable number.

809971621536 is an abundant number, since it is smaller than the sum of its proper divisors (1980361721184).

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

809971621536 is a wasteful number, since it uses less digits than its factorization.

809971621536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5767107 (or 5767099 counting only the distinct ones).

The product of its (nonzero) digits is 4898880, while the sum is 57.

The spelling of 809971621536 in words is "eight hundred nine billion, nine hundred seventy-one million, six hundred twenty-one thousand, five hundred thirty-six".