28144989 has 12 divisors (see below), whose sum is σ = 42159936. Its totient is φ = 18763164.

The previous prime is 28144981. The next prime is 28145003. The reversal of 28144989 is 98944182.

It is not a de Polignac number, because 28144989 - 2³ = 28144981 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28144981) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 57669 + ... + 58154.

It is an arithmetic number, because the mean of its divisors is an integer number (3513328).

Almost surely, 2^28144989 is an apocalyptic number.

It is an amenable number.

28144989 is a deficient number, since it is larger than the sum of its proper divisors (14014947).

28144989 is an equidigital number, since it uses as much as digits as its factorization.

28144989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115838 (or 115826 counting only the distinct ones).

The product of its digits is 165888, while the sum is 45.

The square root of 28144989 is about 5305.1851051589. The cubic root of 28144989 is about 304.1821284273.

The spelling of 28144989 in words is "twenty-eight million, one hundred forty-four thousand, nine hundred eighty-nine".