18307328 has 36 divisors (see below), whose sum is σ = 39361308. Its totient is φ = 8448000.

The previous prime is 18307327. The next prime is 18307339. The reversal of 18307328 is 82370381.

It can be written as a sum of positive squares in 2 ways, for example, as 11505664 + 6801664 = 3392^2 + 2608^2 .

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 18307294 and 18307303.

It is not an unprimeable number, because it can be changed into a prime (18307321) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 578 + ... + 6078.

Almost surely, 2^18307328 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 18307328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19680654).

18307328 is an abundant number, since it is smaller than the sum of its proper divisors (21053980).

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

18307328 is an equidigital number, since it uses as much as digits as its factorization.

18307328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5530 (or 5516 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 18307328 is about 4278.7063465492. The cubic root of 18307328 is about 263.5572622127.

It can be divided in two parts, 18 and 307328, that multiplied together give a square (5531904 = 2352²).

The spelling of 18307328 in words is "eighteen million, three hundred seven thousand, three hundred twenty-eight".