28321217009 has 2 divisors, whose sum is σ = 28321217010. Its totient is φ = 28321217008.

The previous prime is 28321216999. The next prime is 28321217033. The reversal of 28321217009 is 90071212382.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17133501025 + 11187715984 = 130895^2 + 105772^2 .

It is a cyclic number.

It is not a de Polignac number, because 28321217009 - 2¹⁶ = 28321151473 is a prime.

It is a super-3 number, since 3×28321217009³ (a number of 32 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 28321217009.

It is not a weakly prime, because it can be changed into another prime (28321217059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14160608504 + 14160608505.

It is an arithmetic number, because the mean of its divisors is an integer number (14160608505).

Almost surely, 2^28321217009 is an apocalyptic number.

It is an amenable number.

28321217009 is a deficient number, since it is larger than the sum of its proper divisors (1).

28321217009 is an equidigital number, since it uses as much as digits as its factorization.

28321217009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 35.

The spelling of 28321217009 in words is "twenty-eight billion, three hundred twenty-one million, two hundred seventeen thousand, nine".