13645661 has 8 divisors (see below), whose sum is σ = 14046648. Its totient is φ = 13248000.

The previous prime is 13645633. The next prime is 13645691. The reversal of 13645661 is 16654631.

It can be written as a sum of positive squares in 4 ways, for example, as 649636 + 12996025 = 806^2 + 3605^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13645661 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13645691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9191 + ... + 10571.

It is an arithmetic number, because the mean of its divisors is an integer number (1755831).

Almost surely, 2^13645661 is an apocalyptic number.

It is an amenable number.

13645661 is a deficient number, since it is larger than the sum of its proper divisors (400987).

13645661 is a wasteful number, since it uses less digits than its factorization.

13645661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1663.

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

The square root of 13645661 is about 3694.0033838642. The cubic root of 13645661 is about 238.9634754500.

The spelling of 13645661 in words is "thirteen million, six hundred forty-five thousand, six hundred sixty-one".