18322728 has 16 divisors (see below), whose sum is σ = 45806880. Its totient is φ = 6107568.

The previous prime is 18322723. The next prime is 18322729. The reversal of 18322728 is 82722381.

It is a super-2 number, since 2×18322728² = 671444722723968, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18322721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 381700 + ... + 381747.

It is an arithmetic number, because the mean of its divisors is an integer number (2862930).

Almost surely, 2^18322728 is an apocalyptic number.

It is an amenable number.

18322728 is an abundant number, since it is smaller than the sum of its proper divisors (27484152).

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

18322728 is a wasteful number, since it uses less digits than its factorization.

18322728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 763456 (or 763452 counting only the distinct ones).

The product of its digits is 10752, while the sum is 33.

The square root of 18322728 is about 4280.5055776158. The cubic root of 18322728 is about 263.6311423605.

It can be divided in two parts, 1832 and 2728, that added together give a triangular number (4560 = T₉₅).

The spelling of 18322728 in words is "eighteen million, three hundred twenty-two thousand, seven hundred twenty-eight".