13181816 has 8 divisors (see below), whose sum is σ = 24715920. Its totient is φ = 6590904.

The previous prime is 13181809. The next prime is 13181827. The reversal of 13181816 is 61818131.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

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 as a sum of consecutive naturals, namely, 823856 + ... + 823871.

It is an arithmetic number, because the mean of its divisors is an integer number (3089490).

Almost surely, 2^13181816 is an apocalyptic number.

It is an amenable number.

13181816 is a deficient number, since it is larger than the sum of its proper divisors (11534104).

13181816 is a wasteful number, since it uses less digits than its factorization.

13181816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1647733 (or 1647729 counting only the distinct ones).

The product of its digits is 1152, while the sum is 29.

The square root of 13181816 is about 3630.6770718421. The cubic root of 13181816 is about 236.2245779500.

Adding to 13181816 its reverse (61818131), we get a palindrome (74999947).

The spelling of 13181816 in words is "thirteen million, one hundred eighty-one thousand, eight hundred sixteen".