13721818 has 8 divisors (see below), whose sum is σ = 22453920. Its totient is φ = 6237180.

The previous prime is 13721789. The next prime is 13721833. The reversal of 13721818 is 81812731.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

13721818 is a modest number, since divided by 1818 gives 1372 as remainder.

It is a self number, because there is not a number n which added to its sum of digits gives 13721818.

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 3 ways as a sum of consecutive naturals, for example, 311838 + ... + 311881.

It is an arithmetic number, because the mean of its divisors is an integer number (2806740).

Almost surely, 2^13721818 is an apocalyptic number.

13721818 is a deficient number, since it is larger than the sum of its proper divisors (8732102).

13721818 is a wasteful number, since it uses less digits than its factorization.

13721818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 623732.

The product of its digits is 2688, while the sum is 31.

The square root of 13721818 is about 3704.2972342942. The cubic root of 13721818 is about 239.4072060006.

The spelling of 13721818 in words is "thirteen million, seven hundred twenty-one thousand, eight hundred eighteen".