27821745569 has 2 divisors, whose sum is σ = 27821745570. Its totient is φ = 27821745568.

The previous prime is 27821745563. The next prime is 27821745613. The reversal of 27821745569 is 96554712872.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18641806225 + 9179939344 = 136535^2 + 95812^2 .

It is a cyclic number.

It is not a de Polignac number, because 27821745569 - 2⁸ = 27821745313 is a prime.

It is a super-2 number, since 2×27821745569² (a number of 22 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (27821745563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13910872784 + 13910872785.

It is an arithmetic number, because the mean of its divisors is an integer number (13910872785).

Almost surely, 2^27821745569 is an apocalyptic number.

It is an amenable number.

27821745569 is a deficient number, since it is larger than the sum of its proper divisors (1).

27821745569 is an equidigital number, since it uses as much as digits as its factorization.

27821745569 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8467200, while the sum is 56.

The spelling of 27821745569 in words is "twenty-seven billion, eight hundred twenty-one million, seven hundred forty-five thousand, five hundred sixty-nine".