7705728 has 48 divisors (see below), whose sum is σ = 22177350. Its totient is φ = 2568192.

The previous prime is 7705721. The next prime is 7705741. The reversal of 7705728 is 8275077.

It can be written as a sum of positive squares in only one way, i.e., 5419584 + 2286144 = 2328^2 + 1512^2 .

It is a tau number, because it is divible by the number of its divisors (48).

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 = 7705692 and 7705701.

It is not an unprimeable number, because it can be changed into a prime (7705721) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2193 + ... + 4496.

Almost surely, 2^7705728 is an apocalyptic number.

It is an amenable number.

7705728 is an abundant number, since it is smaller than the sum of its proper divisors (14471622).

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

7705728 is a wasteful number, since it uses less digits than its factorization.

7705728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6709 (or 6694 counting only the distinct ones).

The product of its (nonzero) digits is 27440, while the sum is 36.

The square root of 7705728 is about 2775.9193071846. The cubic root of 7705728 is about 197.5170353302.

The spelling of 7705728 in words is "seven million, seven hundred five thousand, seven hundred twenty-eight".