7728645 has 32 divisors (see below), whose sum is σ = 12988800. Its totient is φ = 3919104.

The previous prime is 7728631. The next prime is 7728647. The reversal of 7728645 is 5468277.

It is not a de Polignac number, because 7728645 - 2⁵ = 7728613 is a prime.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7728647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 47334 + ... + 47496.

It is an arithmetic number, because the mean of its divisors is an integer number (405900).

Almost surely, 2^7728645 is an apocalyptic number.

It is an amenable number.

7728645 is a deficient number, since it is larger than the sum of its proper divisors (5260155).

7728645 is a wasteful number, since it uses less digits than its factorization.

7728645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309.

The product of its digits is 94080, while the sum is 39.

The square root of 7728645 is about 2780.0440643990. The cubic root of 7728645 is about 197.7126481695.

The spelling of 7728645 in words is "seven million, seven hundred twenty-eight thousand, six hundred forty-five".