13281665 has 16 divisors (see below), whose sum is σ = 16873920. Its totient is φ = 10008000.

The previous prime is 13281661. The next prime is 13281689. The reversal of 13281665 is 56618231.

It is a happy number.

It is not a de Polignac number, because 13281665 - 2² = 13281661 is a prime.

It is a Curzon number.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (13281661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23567 + ... + 24123.

It is an arithmetic number, because the mean of its divisors is an integer number (1054620).

Almost surely, 2^13281665 is an apocalyptic number.

It is an amenable number.

13281665 is a deficient number, since it is larger than the sum of its proper divisors (3592255).

13281665 is a wasteful number, since it uses less digits than its factorization.

13281665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 832.

The product of its digits is 8640, while the sum is 32.

The square root of 13281665 is about 3644.4018713638. The cubic root of 13281665 is about 236.8195258830.

Adding to 13281665 its reverse (56618231), we get a palindrome (69899896).

The spelling of 13281665 in words is "thirteen million, two hundred eighty-one thousand, six hundred sixty-five".