7225728 has 64 divisors (see below), whose sum is σ = 19845120. Its totient is φ = 2327040.

The previous prime is 7225723. The next prime is 7225739. The reversal of 7225728 is 8275227.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-3 number, since 3×7225728³ (a number of 22 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7225723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11601 + ... + 12207.

It is an arithmetic number, because the mean of its divisors is an integer number (310080).

Almost surely, 2^7225728 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 7225728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9922560).

7225728 is an abundant number, since it is smaller than the sum of its proper divisors (12619392).

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

7225728 is a wasteful number, since it uses less digits than its factorization.

7225728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 655 (or 643 counting only the distinct ones).

The product of its digits is 15680, while the sum is 33.

The square root of 7225728 is about 2688.0714276224. The cubic root of 7225728 is about 193.3276045336.

The spelling of 7225728 in words is "seven million, two hundred twenty-five thousand, seven hundred twenty-eight".