28728555025 has 27 divisors (see below), whose sum is σ = 36069203793. Its totient is φ = 22698770400.

The previous prime is 28728555019. The next prime is 28728555029. The reversal of 28728555025 is 52055582782.

The square root of 28728555025 is 169495.

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 105329169 + 28623225856 = 10263^2 + 169184^2 .

It is not a de Polignac number, because 28728555025 - 2⁵ = 28728554993 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28728555025.

It is not an unprimeable number, because it can be changed into a prime (28728555029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 92374620 + ... + 92374930.

Almost surely, 2^28728555025 is an apocalyptic number.

28728555025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

28728555025 is the 169495-th square number.

28728555025 is the 84748-th centered octagonal number.

It is an amenable number.

28728555025 is a deficient number, since it is larger than the sum of its proper divisors (7340648768).

28728555025 is an frugal number, since it uses more digits than its factorization.

28728555025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 850 (or 425 counting only the distinct ones).

The product of its (nonzero) digits is 2240000, while the sum is 49.

Multiplying 28728555025 by its sum of digits (49), we get a square (1407699196225 = 1186465²).

The spelling of 28728555025 in words is "twenty-eight billion, seven hundred twenty-eight million, five hundred fifty-five thousand, twenty-five".