13611681 has 12 divisors (see below), whose sum is σ = 19693908. Its totient is φ = 9059424.

The previous prime is 13611673. The next prime is 13611691. The reversal of 13611681 is 18611631.

It can be written as a sum of positive squares in 2 ways, for example, as 4665600 + 8946081 = 2160^2 + 2991^2 .

It is not a de Polignac number, because 13611681 - 2³ = 13611673 is a prime.

It is a super-2 number, since 2×13611681² = 370555719291522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (13611691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8371 + ... + 9863.

It is an arithmetic number, because the mean of its divisors is an integer number (1641159).

Almost surely, 2^13611681 is an apocalyptic number.

It is an amenable number.

13611681 is a deficient number, since it is larger than the sum of its proper divisors (6082227).

13611681 is a wasteful number, since it uses less digits than its factorization.

13611681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2512 (or 2509 counting only the distinct ones).

The product of its digits is 864, while the sum is 27.

The square root of 13611681 is about 3689.4011709219. The cubic root of 13611681 is about 238.7649574431.

The spelling of 13611681 in words is "thirteen million, six hundred eleven thousand, six hundred eighty-one".