809964 has 36 divisors (see below), whose sum is σ = 2074800. Its totient is φ = 266400.

The previous prime is 809929. The next prime is 809981. The reversal of 809964 is 469908.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a plaindrome in base 13.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5289 + ... + 5439.

809964 is a Friedman number, since it can be written as 906*894, using all its digits and the basic arithmetic operations.

It is a vampire number, since it can be written as 894 ⋅ 906 (with its own digits).

2⁸⁰⁹⁹⁶⁴ is an apocalyptic number.

It is an amenable number.

809964 is an abundant number, since it is smaller than the sum of its proper divisors (1264836).

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

809964 is a wasteful number, since it uses less digits than its factorization.

809964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 310 (or 305 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 809964 is about 899.9799997778. The cubic root of 809964 is about 93.2155941659.

Adding to 809964 its sum of digits (36), we get a 4-th power (810000 = 30⁴).

The spelling of 809964 in words is "eight hundred nine thousand, nine hundred sixty-four".