28081709 has 8 divisors (see below), whose sum is σ = 28836192. Its totient is φ = 27331920.

The previous prime is 28081681. The next prime is 28081723. The reversal of 28081709 is 90718082.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28081709 - 2¹⁶ = 28016173 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28081769) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13247 + ... + 15219.

It is an arithmetic number, because the mean of its divisors is an integer number (3604524).

Almost surely, 2^28081709 is an apocalyptic number.

It is an amenable number.

28081709 is a deficient number, since it is larger than the sum of its proper divisors (754483).

28081709 is a wasteful number, since it uses less digits than its factorization.

28081709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2347.

The product of its (nonzero) digits is 8064, while the sum is 35.

The square root of 28081709 is about 5299.2177724642. The cubic root of 28081709 is about 303.9539872938.

The spelling of 28081709 in words is "twenty-eight million, eighty-one thousand, seven hundred nine".