7128520 has 48 divisors (see below), whose sum is σ = 18662940. Its totient is φ = 2443392.

The previous prime is 7128509. The next prime is 7128529. The reversal of 7128520 is 258217.

It can be written as a sum of positive squares in 2 ways, for example, as 6140484 + 988036 = 2478^2 + 994^2 .

It is not an unprimeable number, because it can be changed into a prime (7128529) 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 11 ways as a sum of consecutive naturals, for example, 142 + ... + 3778.

Almost surely, 2^7128520 is an apocalyptic number.

7128520 is a gapful number since it is divisible by the number (70) 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 7128520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9331470).

7128520 is an abundant number, since it is smaller than the sum of its proper divisors (11534420).

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

7128520 is a wasteful number, since it uses less digits than its factorization.

7128520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3662 (or 3651 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 25.

The square root of 7128520 is about 2669.9288380030. The cubic root of 7128520 is about 192.4567395901.

The spelling of 7128520 in words is "seven million, one hundred twenty-eight thousand, five hundred twenty".