13205661 has 8 divisors (see below), whose sum is σ = 20122944. Its totient is φ = 7546080.

The previous prime is 13205653. The next prime is 13205663. The reversal of 13205661 is 16650231.

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

It is not a de Polignac number, because 13205661 - 2³ = 13205653 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 (13205663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 314400 + ... + 314441.

It is an arithmetic number, because the mean of its divisors is an integer number (2515368).

Almost surely, 2^13205661 is an apocalyptic number.

It is an amenable number.

13205661 is a deficient number, since it is larger than the sum of its proper divisors (6917283).

13205661 is an equidigital number, since it uses as much as digits as its factorization.

13205661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 628851.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 13205661 is about 3633.9594108906. The cubic root of 13205661 is about 236.3669301630.

Adding to 13205661 its reverse (16650231), we get a palindrome (29855892).

The spelling of 13205661 in words is "thirteen million, two hundred five thousand, six hundred sixty-one".