28005275257 has 4 divisors (see below), whose sum is σ = 28048965876. Its totient is φ = 27961584640.

The previous prime is 28005275251. The next prime is 28005275269. The reversal of 28005275257 is 75257250082.

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

It can be written as a sum of positive squares in 2 ways, for example, as 23729553936 + 4275721321 = 154044^2 + 65389^2 .

It is a cyclic number.

It is not a de Polignac number, because 28005275257 - 2¹¹ = 28005273209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28005275251) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 21844348 + ... + 21845629.

It is an arithmetic number, because the mean of its divisors is an integer number (7012241469).

Almost surely, 2^28005275257 is an apocalyptic number.

It is an amenable number.

28005275257 is a deficient number, since it is larger than the sum of its proper divisors (43690619).

28005275257 is an equidigital number, since it uses as much as digits as its factorization.

28005275257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43690618.

The product of its (nonzero) digits is 392000, while the sum is 43.

The spelling of 28005275257 in words is "twenty-eight billion, five million, two hundred seventy-five thousand, two hundred fifty-seven".