18681344 has 80 divisors (see below), whose sum is σ = 42425856. Its totient is φ = 8140800.

The previous prime is 18681343. The next prime is 18681349. The reversal of 18681344 is 44318681.

It is a super-2 number, since 2×18681344² = 697985227292672, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18681343) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 174539 + ... + 174645.

Almost surely, 2^18681344 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18681344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21212928).

18681344 is an abundant number, since it is smaller than the sum of its proper divisors (23744512).

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

18681344 is a wasteful number, since it uses less digits than its factorization.

18681344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167 (or 151 counting only the distinct ones).

The product of its digits is 18432, while the sum is 35.

The square root of 18681344 is about 4322.1920364556. The cubic root of 18681344 is about 265.3399884417.

The spelling of 18681344 in words is "eighteen million, six hundred eighty-one thousand, three hundred forty-four".