28717739 has 4 divisors (see below), whose sum is σ = 28996656. Its totient is φ = 28438824.

The previous prime is 28717729. The next prime is 28717747. The reversal of 28717739 is 93771782.

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

It is a cyclic number.

It is not a de Polignac number, because 28717739 - 2²⁰ = 27669163 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28717739.

It is not an unprimeable number, because it can be changed into a prime (28717729) 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, 139304 + ... + 139509.

It is an arithmetic number, because the mean of its divisors is an integer number (7249164).

Almost surely, 2^28717739 is an apocalyptic number.

28717739 is a deficient number, since it is larger than the sum of its proper divisors (278917).

28717739 is a wasteful number, since it uses less digits than its factorization.

28717739 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278916.

The product of its digits is 148176, while the sum is 44.

The square root of 28717739 is about 5358.8934492113. The cubic root of 28717739 is about 306.2316549333.

It can be divided in two parts, 2871773 and 9, that added together give a palindrome (2871782).

The spelling of 28717739 in words is "twenty-eight million, seven hundred seventeen thousand, seven hundred thirty-nine".