27649787917 has 2 divisors, whose sum is σ = 27649787918. Its totient is φ = 27649787916.

The previous prime is 27649787897. The next prime is 27649787923. The reversal of 27649787917 is 71978794672.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19162588041 + 8487199876 = 138429^2 + 92126^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27649787917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27649787117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13824893958 + 13824893959.

It is an arithmetic number, because the mean of its divisors is an integer number (13824893959).

Almost surely, 2^27649787917 is an apocalyptic number.

It is an amenable number.

27649787917 is a deficient number, since it is larger than the sum of its proper divisors (1).

27649787917 is an equidigital number, since it uses as much as digits as its factorization.

27649787917 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 74680704, while the sum is 67.

The spelling of 27649787917 in words is "twenty-seven billion, six hundred forty-nine million, seven hundred eighty-seven thousand, nine hundred seventeen".