396809 has 4 divisors (see below), whose sum is σ = 453504. Its totient is φ = 340116.

The previous prime is 396733. The next prime is 396833. The reversal of 396809 is 908693.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 908693 = 569 ⋅1597.

It is a de Polignac number, because none of the positive numbers 2^k-396809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (396509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28337 + ... + 28350.

It is an arithmetic number, because the mean of its divisors is an integer number (113376).

2³⁹⁶⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

396809 is a deficient number, since it is larger than the sum of its proper divisors (56695).

396809 is an equidigital number, since it uses as much as digits as its factorization.

396809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56694.

The product of its (nonzero) digits is 11664, while the sum is 35.

The square root of 396809 is about 629.9277736376. The cubic root of 396809 is about 73.4841775681.

The spelling of 396809 in words is "three hundred ninety-six thousand, eight hundred nine".