812321 has 4 divisors (see below), whose sum is σ = 822192. Its totient is φ = 802452.

The previous prime is 812309. The next prime is 812341. The reversal of 812321 is 123218.

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: 123218 = 2 ⋅61609.

It is a cyclic number.

It is not a de Polignac number, because 812321 - 2⁶ = 812257 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a nialpdrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 812321.

It is not an unprimeable number, because it can be changed into a prime (812341) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4811 + ... + 4976.

It is an arithmetic number, because the mean of its divisors is an integer number (205548).

2⁸¹²³²¹ is an apocalyptic number.

It is an amenable number.

812321 is a deficient number, since it is larger than the sum of its proper divisors (9871).

812321 is an equidigital number, since it uses as much as digits as its factorization.

812321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9870.

The product of its digits is 96, while the sum is 17.

The square root of 812321 is about 901.2885220616. The cubic root of 812321 is about 93.3059259095.

Adding to 812321 its reverse (123218), we get a palindrome (935539).

The spelling of 812321 in words is "eight hundred twelve thousand, three hundred twenty-one".