28044689 has 4 divisors (see below), whose sum is σ = 28504500. Its totient is φ = 27584880.

The previous prime is 28044617. The next prime is 28044691. The reversal of 28044689 is 98644082.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8614225 + 19430464 = 2935^2 + 4408^2 .

It is a cyclic number.

It is not a de Polignac number, because 28044689 - 2⁸ = 28044433 is a prime.

It is a super-2 number, since 2×28044689² = 1573009162213442, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28044389) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 229814 + ... + 229935.

It is an arithmetic number, because the mean of its divisors is an integer number (7126125).

Almost surely, 2^28044689 is an apocalyptic number.

It is an amenable number.

28044689 is a deficient number, since it is larger than the sum of its proper divisors (459811).

28044689 is an equidigital number, since it uses as much as digits as its factorization.

28044689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 459810.

The product of its (nonzero) digits is 110592, while the sum is 41.

The square root of 28044689 is about 5295.7236521556. The cubic root of 28044689 is about 303.8203614654.

The spelling of 28044689 in words is "twenty-eight million, forty-four thousand, six hundred eighty-nine".