13206661 has 4 divisors (see below), whose sum is σ = 14222572. Its totient is φ = 12190752.

The previous prime is 13206631. The next prime is 13206679. The reversal of 13206661 is 16660231.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2356225 + 10850436 = 1535^2 + 3294^2 .

It is a cyclic number.

It is not a de Polignac number, because 13206661 - 2¹⁷ = 13075589 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13206601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 507936 + ... + 507961.

It is an arithmetic number, because the mean of its divisors is an integer number (3555643).

Almost surely, 2^13206661 is an apocalyptic number.

It is an amenable number.

13206661 is a deficient number, since it is larger than the sum of its proper divisors (1015911).

13206661 is a wasteful number, since it uses less digits than its factorization.

13206661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1015910.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 13206661 is about 3634.0969992558. The cubic root of 13206661 is about 236.3728963155.

Adding to 13206661 its reverse (16660231), we get a palindrome (29866892).

The spelling of 13206661 in words is "thirteen million, two hundred six thousand, six hundred sixty-one".