13251661 has 4 divisors (see below), whose sum is σ = 13609852. Its totient is φ = 12893472.

The previous prime is 13251659. The next prime is 13251709. The reversal of 13251661 is 16615231.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16615231 = 29 ⋅572939.

It can be written as a sum of positive squares in 2 ways, for example, as 5929225 + 7322436 = 2435^2 + 2706^2 .

It is a cyclic number.

It is not a de Polignac number, because 13251661 - 2¹ = 13251659 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13251361) 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, 179040 + ... + 179113.

It is an arithmetic number, because the mean of its divisors is an integer number (3402463).

Almost surely, 2^13251661 is an apocalyptic number.

It is an amenable number.

13251661 is a deficient number, since it is larger than the sum of its proper divisors (358191).

13251661 is an equidigital number, since it uses as much as digits as its factorization.

13251661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 358190.

The product of its digits is 1080, while the sum is 25.

The square root of 13251661 is about 3640.2830933871. The cubic root of 13251661 is about 236.6410620540.

Adding to 13251661 its reverse (16615231), we get a palindrome (29866892).

The spelling of 13251661 in words is "thirteen million, two hundred fifty-one thousand, six hundred sixty-one".