13311918 has 48 divisors (see below), whose sum is σ = 31461360. Its totient is φ = 4171392.

The previous prime is 13311911. The next prime is 13311929. The reversal of 13311918 is 81911331.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 13311891 and 13311900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13311911) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15180 + ... + 16032.

It is an arithmetic number, because the mean of its divisors is an integer number (655445).

Almost surely, 2^13311918 is an apocalyptic number.

13311918 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 13311918, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15730680).

13311918 is an abundant number, since it is smaller than the sum of its proper divisors (18149442).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

13311918 is a wasteful number, since it uses less digits than its factorization.

13311918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 898 (or 875 counting only the distinct ones).

The product of its digits is 648, while the sum is 27.

The square root of 13311918 is about 3648.5501229941. The cubic root of 13311918 is about 236.9991988436. Note that the first 3 decimals are identical.

It can be divided in two parts, 1331 and 1918, that added together give a square (3249 = 57²).

The spelling of 13311918 in words is "thirteen million, three hundred eleven thousand, nine hundred eighteen".