28188727691 has 2 divisors, whose sum is σ = 28188727692. Its totient is φ = 28188727690.

The previous prime is 28188727669. The next prime is 28188727741. The reversal of 28188727691 is 19672788182.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28188727691 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28188727691.

It is not a weakly prime, because it can be changed into another prime (28188727631) 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, 14094363845 + 14094363846.

It is an arithmetic number, because the mean of its divisors is an integer number (14094363846).

Almost surely, 2^28188727691 is an apocalyptic number.

28188727691 is a deficient number, since it is larger than the sum of its proper divisors (1).

28188727691 is an equidigital number, since it uses as much as digits as its factorization.

28188727691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5419008, while the sum is 59.

The spelling of 28188727691 in words is "twenty-eight billion, one hundred eighty-eight million, seven hundred twenty-seven thousand, six hundred ninety-one".