28320642409 has 2 divisors, whose sum is σ = 28320642410. Its totient is φ = 28320642408.

The previous prime is 28320642401. The next prime is 28320642419. The reversal of 28320642409 is 90424602382.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25903936809 + 2416705600 = 160947^2 + 49160^2 .

It is a cyclic number.

It is not a de Polignac number, because 28320642409 - 2³ = 28320642401 is a prime.

It is not a weakly prime, because it can be changed into another prime (28320642401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14160321204 + 14160321205.

It is an arithmetic number, because the mean of its divisors is an integer number (14160321205).

Almost surely, 2^28320642409 is an apocalyptic number.

It is an amenable number.

28320642409 is a deficient number, since it is larger than the sum of its proper divisors (1).

28320642409 is an equidigital number, since it uses as much as digits as its factorization.

28320642409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 165888, while the sum is 40.

The spelling of 28320642409 in words is "twenty-eight billion, three hundred twenty million, six hundred forty-two thousand, four hundred nine".