28065085666 has 4 divisors (see below), whose sum is σ = 42097628502. Its totient is φ = 14032542832.

The previous prime is 28065085651. The next prime is 28065085669. The reversal of 28065085666 is 66658056082.

It is a happy number.

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

It can be written as a sum of positive squares in only one way, i.e., 24509468025 + 3555617641 = 156555^2 + 59629^2 .

It is not an unprimeable number, because it can be changed into a prime (28065085669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7016271415 + ... + 7016271418.

Almost surely, 2^28065085666 is an apocalyptic number.

28065085666 is a deficient number, since it is larger than the sum of its proper divisors (14032542836).

28065085666 is a wasteful number, since it uses less digits than its factorization.

28065085666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14032542835.

The product of its (nonzero) digits is 4147200, while the sum is 52.

The spelling of 28065085666 in words is "twenty-eight billion, sixty-five million, eighty-five thousand, six hundred sixty-six".