28668923705 has 8 divisors (see below), whose sum is σ = 34406644104. Its totient is φ = 22932515200.

The previous prime is 28668923687. The next prime is 28668923711. The reversal of 28668923705 is 50732986682.

It can be written as a sum of positive squares in 4 ways, for example, as 8140911529 + 20528012176 = 90227^2 + 143276^2 .

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

It is not a de Polignac number, because 28668923705 - 2¹⁸ = 28668661561 is a prime.

It is a super-2 number, since 2×28668923705² (a number of 22 digits) contains 22 as substring.

It is a Duffinian 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, 279236 + ... + 367845.

It is an arithmetic number, because the mean of its divisors is an integer number (4300830513).

Almost surely, 2^28668923705 is an apocalyptic number.

It is an amenable number.

28668923705 is a deficient number, since it is larger than the sum of its proper divisors (5737720399).

28668923705 is an equidigital number, since it uses as much as digits as its factorization.

28668923705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 655947.

The product of its (nonzero) digits is 8709120, while the sum is 56.

Adding to 28668923705 its sum of digits (56), we get a square (28668923761 = 169319²).

The spelling of 28668923705 in words is "twenty-eight billion, six hundred sixty-eight million, nine hundred twenty-three thousand, seven hundred five".