13661661 has 16 divisors (see below), whose sum is σ = 19756800. Its totient is φ = 8347200.

The previous prime is 13661647. The next prime is 13661663. The reversal of 13661661 is 16616631.

13661661 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 13661661 - 2¹⁰ = 13660637 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13661663) 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, 4636 + ... + 6986.

It is an arithmetic number, because the mean of its divisors is an integer number (1234800).

Almost surely, 2^13661661 is an apocalyptic number.

It is an amenable number.

13661661 is a deficient number, since it is larger than the sum of its proper divisors (6095139).

13661661 is a wasteful number, since it uses less digits than its factorization.

13661661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2516.

The product of its digits is 3888, while the sum is 30.

The square root of 13661661 is about 3696.1684214873. The cubic root of 13661661 is about 239.0568365611.

The spelling of 13661661 in words is "thirteen million, six hundred sixty-one thousand, six hundred sixty-one".