28317881665 has 8 divisors (see below), whose sum is σ = 35980367400. Its totient is φ = 21321699072.

The previous prime is 28317881639. The next prime is 28317881693. The reversal of 28317881665 is 56618871382.

It can be written as a sum of positive squares in 4 ways, for example, as 1463521536 + 26854360129 = 38256^2 + 163873^2 .

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 28317881665 - 2¹¹ = 28317879617 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 166575690 + ... + 166575859.

It is an arithmetic number, because the mean of its divisors is an integer number (4497545925).

Almost surely, 2^28317881665 is an apocalyptic number.

It is an amenable number.

28317881665 is a deficient number, since it is larger than the sum of its proper divisors (7662485735).

28317881665 is a wasteful number, since it uses less digits than its factorization.

28317881665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333151571.

The product of its digits is 3870720, while the sum is 55.

The spelling of 28317881665 in words is "twenty-eight billion, three hundred seventeen million, eight hundred eighty-one thousand, six hundred sixty-five".