28325899809 has 9 divisors (see below), whose sum is σ = 40915917939. Its totient is φ = 18883596600.

The previous prime is 28325899733. The next prime is 28325899871. The reversal of 28325899809 is 90899852382.

The square root of 28325899809 is 168303.

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

It can be written as a sum of positive squares in only one way, i.e., 18345889809 + 9980010000 = 135447^2 + 99900^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 28325899809 - 2²¹ = 28323802657 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28325899009) 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 8 ways as a sum of consecutive naturals, for example, 476859 + ... + 532959.

Almost surely, 2^28325899809 is an apocalyptic number.

28325899809 is the 168303-rd square number.

28325899809 is the 84152-nd centered octagonal number.

It is an amenable number.

28325899809 is a deficient number, since it is larger than the sum of its proper divisors (12590018130).

28325899809 is an frugal number, since it uses more digits than its factorization.

28325899809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112208 (or 56104 counting only the distinct ones).

The product of its (nonzero) digits is 22394880, while the sum is 63.

The spelling of 28325899809 in words is "twenty-eight billion, three hundred twenty-five million, eight hundred ninety-nine thousand, eight hundred nine".