12851809 has 4 divisors (see below), whose sum is σ = 13528240. Its totient is φ = 12175380.

The previous prime is 12851791. The next prime is 12851831. The reversal of 12851809 is 90815821.

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: 90815821 = 103 ⋅881707.

It is a cyclic number.

It is not a de Polignac number, because 12851809 - 2⁵ = 12851777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12851849) 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, 338187 + ... + 338224.

It is an arithmetic number, because the mean of its divisors is an integer number (3382060).

Almost surely, 2^12851809 is an apocalyptic number.

12851809 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

12851809 is a deficient number, since it is larger than the sum of its proper divisors (676431).

12851809 is an equidigital number, since it uses as much as digits as its factorization.

12851809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 676430.

The product of its (nonzero) digits is 5760, while the sum is 34.

The square root of 12851809 is about 3584.9419800047. The cubic root of 12851809 is about 234.2365992728.

The spelling of 12851809 in words is "twelve million, eight hundred fifty-one thousand, eight hundred nine".