28140205685 has 8 divisors (see below), whose sum is σ = 33771547320. Its totient is φ = 22509964224.

The previous prime is 28140205679. The next prime is 28140205693. The reversal of 28140205685 is 58650204182.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 11054840164 + 17085365521 = 105142^2 + 130711^2 .

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 28140205685 - 2¹⁰ = 28140204661 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 217682 + ... + 321971.

It is an arithmetic number, because the mean of its divisors is an integer number (4221443415).

Almost surely, 2^28140205685 is an apocalyptic number.

It is an amenable number.

28140205685 is a deficient number, since it is larger than the sum of its proper divisors (5631341635).

28140205685 is a wasteful number, since it uses less digits than its factorization.

28140205685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 550087.

The product of its (nonzero) digits is 153600, while the sum is 41.

The spelling of 28140205685 in words is "twenty-eight billion, one hundred forty million, two hundred five thousand, six hundred eighty-five".