18315616 has 48 divisors (see below), whose sum is σ = 40028688. Its totient is φ = 8179200.

The previous prime is 18315607. The next prime is 18315631. The reversal of 18315616 is 61651381.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21046 + ... + 21898.

It is an arithmetic number, because the mean of its divisors is an integer number (833931).

Almost surely, 2^18315616 is an apocalyptic number.

18315616 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18315616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20014344).

18315616 is an abundant number, since it is smaller than the sum of its proper divisors (21713072).

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

18315616 is a wasteful number, since it uses less digits than its factorization.

18315616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 935 (or 927 counting only the distinct ones).

The product of its digits is 4320, while the sum is 31.

The square root of 18315616 is about 4279.6747539971. The cubic root of 18315616 is about 263.5970283114.

Adding to 18315616 its reverse (61651381), we get a palindrome (79966997).

It can be divided in two parts, 1831 and 5616, that added together give a palindrome (7447).

The spelling of 18315616 in words is "eighteen million, three hundred fifteen thousand, six hundred sixteen".