812409 has 16 divisors (see below), whose sum is σ = 1200192. Its totient is φ = 485568.

The previous prime is 812401. The next prime is 812431. The reversal of 812409 is 904218.

It is not a de Polignac number, because 812409 - 2³ = 812401 is a prime.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (812401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1162 + ... + 1724.

It is an arithmetic number, because the mean of its divisors is an integer number (75012).

2⁸¹²⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

812409 is a deficient number, since it is larger than the sum of its proper divisors (387783).

812409 is a wasteful number, since it uses less digits than its factorization.

812409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 616.

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 812409 is about 901.3373397347. The cubic root of 812409 is about 93.3092951133.

Subtracting 812409 from its reverse (904218), we obtain a square (91809 = 303²).

It can be divided in two parts, 812 and 409, that added together give a palindrome (1221).

The spelling of 812409 in words is "eight hundred twelve thousand, four hundred nine".