27721852817 has 2 divisors, whose sum is σ = 27721852818. Its totient is φ = 27721852816.

The previous prime is 27721852813. The next prime is 27721852849. The reversal of 27721852817 is 71825812772.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26789832976 + 932019841 = 163676^2 + 30529^2 .

It is a cyclic number.

It is not a de Polignac number, because 27721852817 - 2² = 27721852813 is a prime.

It is a super-2 number, since 2×27721852817² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (27721852813) 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 as a sum of consecutive naturals, namely, 13860926408 + 13860926409.

It is an arithmetic number, because the mean of its divisors is an integer number (13860926409).

Almost surely, 2^27721852817 is an apocalyptic number.

It is an amenable number.

27721852817 is a deficient number, since it is larger than the sum of its proper divisors (1).

27721852817 is an equidigital number, since it uses as much as digits as its factorization.

27721852817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 878080, while the sum is 50.

The spelling of 27721852817 in words is "twenty-seven billion, seven hundred twenty-one million, eight hundred fifty-two thousand, eight hundred seventeen".