13646561 has 4 divisors (see below), whose sum is σ = 13654212. Its totient is φ = 13638912.

The previous prime is 13646537. The next prime is 13646569. The reversal of 13646561 is 16564631.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 16564631 = 3163 ⋅5237.

It can be written as a sum of positive squares in 2 ways, for example, as 3045025 + 10601536 = 1745^2 + 3256^2 .

It is a cyclic number.

It is not a de Polignac number, because 13646561 - 2¹⁰ = 13645537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13646569) 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, 425 + ... + 5241.

It is an arithmetic number, because the mean of its divisors is an integer number (3413553).

Almost surely, 2^13646561 is an apocalyptic number.

It is an amenable number.

13646561 is a deficient number, since it is larger than the sum of its proper divisors (7651).

13646561 is an equidigital number, since it uses as much as digits as its factorization.

13646561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7650.

The product of its digits is 12960, while the sum is 32.

The square root of 13646561 is about 3694.1252009102. The cubic root of 13646561 is about 238.9687289490.

The spelling of 13646561 in words is "thirteen million, six hundred forty-six thousand, five hundred sixty-one".