13209805 has 16 divisors (see below), whose sum is σ = 18426240. Its totient is φ = 8903232.

The previous prime is 13209793. The next prime is 13209821. The reversal of 13209805 is 50890231.

It is a cyclic number.

It is not a de Polignac number, because 13209805 - 2⁹ = 13209293 is a prime.

It is a congruent number.

It is an unprimeable number.

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, 1134 + ... + 5263.

It is an arithmetic number, because the mean of its divisors is an integer number (1151640).

Almost surely, 2^13209805 is an apocalyptic number.

It is an amenable number.

13209805 is a deficient number, since it is larger than the sum of its proper divisors (5216435).

13209805 is an equidigital number, since it uses as much as digits as its factorization.

13209805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6468.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 13209805 is about 3634.5295431459. The cubic root of 13209805 is about 236.3916519375.

It can be divided in two parts, 1320980 and 5, that multiplied together give a square (6604900 = 2570²).

The spelling of 13209805 in words is "thirteen million, two hundred nine thousand, eight hundred five".