13212809 has 4 divisors (see below), whose sum is σ = 13908240. Its totient is φ = 12517380.

The previous prime is 13212803. The next prime is 13212817. The reversal of 13212809 is 90821231.

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: 90821231 = 1889 ⋅48079.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13212809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13212803) 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 3 ways as a sum of consecutive naturals, for example, 347687 + ... + 347724.

It is an arithmetic number, because the mean of its divisors is an integer number (3477060).

Almost surely, 2^13212809 is an apocalyptic number.

13212809 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

13212809 is a deficient number, since it is larger than the sum of its proper divisors (695431).

13212809 is an equidigital number, since it uses as much as digits as its factorization.

13212809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 695430.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 13212809 is about 3634.9427780916. The cubic root of 13212809 is about 236.4095696054.

The spelling of 13212809 in words is "thirteen million, two hundred twelve thousand, eight hundred nine".