7728928209025 has 27 divisors (see below), whose sum is σ = 10181101560969. Its totient is φ = 5819250372480.

The previous prime is 7728928208959. The next prime is 7728928209071. The reversal of 7728928209025 is 5209028298277.

The square root of 7728928209025 is 2780095.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 180787386481 + 7548140822544 = 425191^2 + 2747388^2 .

It is not a de Polignac number, because 7728928209025 - 2¹⁵ = 7728928176257 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 236291722 + ... + 236324428.

Almost surely, 2^{7728928209025} is an apocalyptic number.

7728928209025 is the 2780095-th square number.

7728928209025 is the 1390048-th centered octagonal number.

It is an amenable number.

7728928209025 is a deficient number, since it is larger than the sum of its proper divisors (2452173351944).

7728928209025 is an frugal number, since it uses more digits than its factorization.

7728928209025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65458 (or 32729 counting only the distinct ones).

The product of its (nonzero) digits is 20321280, while the sum is 61.

The spelling of 7728928209025 in words is "seven trillion, seven hundred twenty-eight billion, nine hundred twenty-eight million, two hundred nine thousand, twenty-five".