13781118 has 64 divisors (see below), whose sum is σ = 33143040. Its totient is φ = 3773952.

The previous prime is 13781107. The next prime is 13781123. The reversal of 13781118 is 81118731.

It is a happy number.

13781118 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 24921 + ... + 25467.

It is an arithmetic number, because the mean of its divisors is an integer number (517860).

Almost surely, 2^13781118 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 13781118, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16571520).

13781118 is an abundant number, since it is smaller than the sum of its proper divisors (19361922).

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

13781118 is a wasteful number, since it uses less digits than its factorization.

13781118 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 601.

The product of its digits is 1344, while the sum is 30.

The square root of 13781118 is about 3712.2928225020. The cubic root of 13781118 is about 239.7515832378.

Adding to 13781118 its reverse (81118731), we get a palindrome (94899849).

The spelling of 13781118 in words is "thirteen million, seven hundred eighty-one thousand, one hundred eighteen".