28640485225 has 81 divisors (see below), whose sum is σ = 41697964623. Its totient is φ = 19495872000.

The previous prime is 28640485219. The next prime is 28640485229. The reversal of 28640485225 is 52258404682.

The square root of 28640485225 is 169235.

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

It can be written as a sum of positive squares in 13 ways, for example, as 26765941609 + 1874543616 = 163603^2 + 43296^2 .

It is a de Polignac number, because none of the positive numbers 2^k-28640485225 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28640485229) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 158234635 + ... + 158234815.

Almost surely, 2^28640485225 is an apocalyptic number.

28640485225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

28640485225 is the 169235-th square number.

28640485225 is the 84618-th centered octagonal number.

It is an amenable number.

28640485225 is a deficient number, since it is larger than the sum of its proper divisors (13057479398).

28640485225 is a wasteful number, since it uses less digits than its factorization.

28640485225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 428 (or 214 counting only the distinct ones).

The product of its (nonzero) digits is 1228800, while the sum is 46.

The spelling of 28640485225 in words is "twenty-eight billion, six hundred forty million, four hundred eighty-five thousand, two hundred twenty-five".