28751821871 has 2 divisors, whose sum is σ = 28751821872. Its totient is φ = 28751821870.

The previous prime is 28751821867. The next prime is 28751821939. The reversal of 28751821871 is 17812815782.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28751821871 - 2² = 28751821867 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28751821771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14375910935 + 14375910936.

It is an arithmetic number, because the mean of its divisors is an integer number (14375910936).

Almost surely, 2^28751821871 is an apocalyptic number.

28751821871 is a deficient number, since it is larger than the sum of its proper divisors (1).

28751821871 is an equidigital number, since it uses as much as digits as its factorization.

28751821871 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 501760, while the sum is 50.

The spelling of 28751821871 in words is "twenty-eight billion, seven hundred fifty-one million, eight hundred twenty-one thousand, eight hundred seventy-one".