28508874721 has 2 divisors, whose sum is σ = 28508874722. Its totient is φ = 28508874720.

The previous prime is 28508874707. The next prime is 28508874791. The reversal of 28508874721 is 12747880582.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28175301025 + 333573696 = 167855^2 + 18264^2 .

It is a cyclic number.

It is not a de Polignac number, because 28508874721 - 2⁹ = 28508874209 is a prime.

It is a super-3 number, since 3×28508874721³ (a number of 32 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (28508874791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14254437360 + 14254437361.

It is an arithmetic number, because the mean of its divisors is an integer number (14254437361).

Almost surely, 2^28508874721 is an apocalyptic number.

It is an amenable number.

28508874721 is a deficient number, since it is larger than the sum of its proper divisors (1).

28508874721 is an equidigital number, since it uses as much as digits as its factorization.

28508874721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2007040, while the sum is 52.

The spelling of 28508874721 in words is "twenty-eight billion, five hundred eight million, eight hundred seventy-four thousand, seven hundred twenty-one".