18005312 has 112 divisors (see below), whose sum is σ = 43525440. Its totient is φ = 7299072.

The previous prime is 18005291. The next prime is 18005333. The reversal of 18005312 is 21350081.

It is an interprime number because it is at equal distance from previous prime (18005291) and next prime (18005333).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 268703 + ... + 268769.

It is an arithmetic number, because the mean of its divisors is an integer number (388620).

Almost surely, 2^18005312 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 18005312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21762720).

18005312 is an abundant number, since it is smaller than the sum of its proper divisors (25520128).

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

18005312 is a wasteful number, since it uses less digits than its factorization.

18005312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128 (or 118 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 18005312 is about 4243.2666661430. The cubic root of 18005312 is about 262.0999172154.

Adding to 18005312 its reverse (21350081), we get a palindrome (39355393).

The spelling of 18005312 in words is "eighteen million, five thousand, three hundred twelve".