28644489 has 16 divisors (see below), whose sum is σ = 43900800. Its totient is φ = 18437328.

The previous prime is 28644467. The next prime is 28644491. The reversal of 28644489 is 98444682.

It is not a de Polignac number, because 28644489 - 2⁸ = 28644233 is a prime.

It is a super-2 number, since 2×28644489² = 1641013500142242, which contains 22 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (28644089) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17509 + ... + 19074.

It is an arithmetic number, because the mean of its divisors is an integer number (2743800).

Almost surely, 2^28644489 is an apocalyptic number.

28644489 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

28644489 is a deficient number, since it is larger than the sum of its proper divisors (15256311).

28644489 is a wasteful number, since it uses less digits than its factorization.

28644489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36621 (or 36615 counting only the distinct ones).

The product of its digits is 442368, while the sum is 45.

The square root of 28644489 is about 5352.0546521873. The cubic root of 28644489 is about 305.9710660839.

The spelling of 28644489 in words is "twenty-eight million, six hundred forty-four thousand, four hundred eighty-nine".