809819956 has 24 divisors (see below), whose sum is σ = 1636963776. Its totient is φ = 346446720.

The previous prime is 809819891. The next prime is 809819963. The reversal of 809819956 is 659918908.

It is a super-2 number, since 2×809819956² = 1311616722271683872, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 809819897 and 809819906.

It is a congruent number.

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, 540576 + ... + 542071.

It is an arithmetic number, because the mean of its divisors is an integer number (68206824).

Almost surely, 2^809819956 is an apocalyptic number.

It is an amenable number.

809819956 is an abundant number, since it is smaller than the sum of its proper divisors (827143820).

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

809819956 is a wasteful number, since it uses less digits than its factorization.

809819956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1082679 (or 1082677 counting only the distinct ones).

The product of its (nonzero) digits is 1399680, while the sum is 55.

The square root of 809819956 is about 28457.3357150665. The cubic root of 809819956 is about 932.1006801782.

It can be divided in two parts, 80981995 and 6, that added together give a square (80982001 = 8999²).

The spelling of 809819956 in words is "eight hundred nine million, eight hundred nineteen thousand, nine hundred fifty-six".