13686181 has 4 divisors (see below), whose sum is σ = 13755852. Its totient is φ = 13616512.

The previous prime is 13686133. The next prime is 13686191. The reversal of 13686181 is 18168631.

13686181 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 11329956 + 2356225 = 3366^2 + 1535^2 .

It is a cyclic number.

It is not a de Polignac number, because 13686181 - 2⁹ = 13685669 is a prime.

It is a super-2 number, since 2×13686181² = 374623100729522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13686121) 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, 34540 + ... + 34933.

It is an arithmetic number, because the mean of its divisors is an integer number (3438963).

Almost surely, 2^13686181 is an apocalyptic number.

It is an amenable number.

13686181 is a deficient number, since it is larger than the sum of its proper divisors (69671).

13686181 is an equidigital number, since it uses as much as digits as its factorization.

13686181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69670.

The product of its digits is 6912, while the sum is 34.

The square root of 13686181 is about 3699.4838829220. The cubic root of 13686181 is about 239.1997711153.

The spelling of 13686181 in words is "thirteen million, six hundred eighty-six thousand, one hundred eighty-one".