28144389 has 16 divisors (see below), whose sum is σ = 46186112. Its totient is φ = 14845248.

The previous prime is 28144331. The next prime is 28144393. The reversal of 28144389 is 98344182.

It is not a de Polignac number, because 28144389 - 2⁷ = 28144261 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28144189) 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 15 ways as a sum of consecutive naturals, for example, 51274 + ... + 51819.

It is an arithmetic number, because the mean of its divisors is an integer number (2886632).

Almost surely, 2^28144389 is an apocalyptic number.

It is an amenable number.

28144389 is a deficient number, since it is larger than the sum of its proper divisors (18041723).

28144389 is a wasteful number, since it uses less digits than its factorization.

28144389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103116.

The product of its digits is 55296, while the sum is 39.

The square root of 28144389 is about 5305.1285564065. The cubic root of 28144389 is about 304.1799668753.

The spelling of 28144389 in words is "twenty-eight million, one hundred forty-four thousand, three hundred eighty-nine".