28398825 has 144 divisors (see below), whose sum is σ = 66801280. Its totient is φ = 11197440.

The previous prime is 28398817. The next prime is 28398829. The reversal of 28398825 is 52889382.

It is not a de Polignac number, because 28398825 - 2³ = 28398817 is a prime.

It is a super-2 number, since 2×28398825² = 1612986522761250, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

Its product of digits (276480) is a multiple of the sum of its prime divisors (120).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28398829) 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 143 ways as a sum of consecutive naturals, for example, 388989 + ... + 389061.

Almost surely, 2^28398825 is an apocalyptic number.

28398825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28398825 is an abundant number, since it is smaller than the sum of its proper divisors (38402455).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28398825 is a wasteful number, since it uses less digits than its factorization.

28398825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128 (or 120 counting only the distinct ones).

The product of its digits is 276480, while the sum is 45.

The square root of 28398825 is about 5329.0547942388. The cubic root of 28398825 is about 305.0938526903.

It can be divided in two parts, 2839 and 8825, that added together give a square (11664 = 108²).

The spelling of 28398825 in words is "twenty-eight million, three hundred ninety-eight thousand, eight hundred twenty-five".