809861312 has 56 divisors (see below), whose sum is σ = 1771016016. Its totient is φ = 365073408.

The previous prime is 809861251. The next prime is 809861321. The reversal of 809861312 is 213168908.

It is a super-2 number, since 2×809861312² = 1311750689348722688, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24458 + ... + 47094.

It is an arithmetic number, because the mean of its divisors is an integer number (31625286).

Almost surely, 2^809861312 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 809861312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (885508008).

809861312 is an abundant number, since it is smaller than the sum of its proper divisors (961154704).

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

809861312 is a wasteful number, since it uses less digits than its factorization.

809861312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22705 (or 22695 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 38.

The square root of 809861312 is about 28458.0623374115. The cubic root of 809861312 is about 932.1165467912.

The spelling of 809861312 in words is "eight hundred nine million, eight hundred sixty-one thousand, three hundred twelve".