13661818 has 4 divisors (see below), whose sum is σ = 20492730. Its totient is φ = 6830908.

The previous prime is 13661803. The next prime is 13661833. The reversal of 13661818 is 81816631.

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

It is an interprime number because it is at equal distance from previous prime (13661803) and next prime (13661833).

It can be written as a sum of positive squares in only one way, i.e., 12229009 + 1432809 = 3497^2 + 1197^2 .

13661818 is a modest number, since divided by 1818 gives 1366 as remainder.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 3415453 + ... + 3415456.

Almost surely, 2^13661818 is an apocalyptic number.

13661818 is a deficient number, since it is larger than the sum of its proper divisors (6830912).

13661818 is an equidigital number, since it uses as much as digits as its factorization.

13661818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6830911.

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

The square root of 13661818 is about 3696.1896596360. The cubic root of 13661818 is about 239.0577523058.

The spelling of 13661818 in words is "thirteen million, six hundred sixty-one thousand, eight hundred eighteen".