13561866 has 12 divisors (see below), whose sum is σ = 29384082. Its totient is φ = 4520616.

The previous prime is 13561859. The next prime is 13561883. The reversal of 13561866 is 66816531.

It is a happy number.

13561866 is a `hidden beast` number, since 1 + 35 + 618 + 6 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 7700625 + 5861241 = 2775^2 + 2421^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 13561866.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 376701 + ... + 376736.

Almost surely, 2^13561866 is an apocalyptic number.

13561866 is an abundant number, since it is smaller than the sum of its proper divisors (15822216).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

13561866 is a wasteful number, since it uses less digits than its factorization.

13561866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 753445 (or 753442 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 13561866 is about 3682.6438872093. The cubic root of 13561866 is about 238.4733300874.

It can be divided in two parts, 135 and 61866, that added together give a square (62001 = 249²).

The spelling of 13561866 in words is "thirteen million, five hundred sixty-one thousand, eight hundred sixty-six".