13281605 has 4 divisors (see below), whose sum is σ = 15937932. Its totient is φ = 10625280.

The previous prime is 13281571. The next prime is 13281613. The reversal of 13281605 is 50618231.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6385729 + 6895876 = 2527^2 + 2626^2 .

It is not a de Polignac number, because 13281605 - 2¹⁶ = 13216069 is a prime.

It is a Duffinian number.

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 3 ways as a sum of consecutive naturals, for example, 1328156 + ... + 1328165.

It is an arithmetic number, because the mean of its divisors is an integer number (3984483).

Almost surely, 2^13281605 is an apocalyptic number.

It is an amenable number.

13281605 is a deficient number, since it is larger than the sum of its proper divisors (2656327).

13281605 is an equidigital number, since it uses as much as digits as its factorization.

13281605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2656326.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 13281605 is about 3644.3936395510. The cubic root of 13281605 is about 236.8191692712.

Adding to 13281605 its reverse (50618231), we get a palindrome (63899836).

The spelling of 13281605 in words is "thirteen million, two hundred eighty-one thousand, six hundred five".