7381728 has 108 divisors (see below), whose sum is σ = 22466808. Its totient is φ = 2298240.

The previous prime is 7381721. The next prime is 7381729. The reversal of 7381728 is 8271837.

It is a super-3 number, since 3×7381728³ (a number of 22 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 7381692 and 7381701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7381721) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 103933 + ... + 104003.

It is an arithmetic number, because the mean of its divisors is an integer number (208026).

Almost surely, 2^7381728 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 7381728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11233404).

7381728 is an abundant number, since it is smaller than the sum of its proper divisors (15085080).

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

7381728 is a wasteful number, since it uses less digits than its factorization.

7381728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125 (or 95 counting only the distinct ones).

The product of its digits is 18816, while the sum is 36.

The square root of 7381728 is about 2716.9335656214. The cubic root of 7381728 is about 194.7089939443.

The spelling of 7381728 in words is "seven million, three hundred eighty-one thousand, seven hundred twenty-eight".