27800765917 has 2 divisors, whose sum is σ = 27800765918. Its totient is φ = 27800765916.

The previous prime is 27800765911. The next prime is 27800765953. The reversal of 27800765917 is 71956700872.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23229112921 + 4571652996 = 152411^2 + 67614^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27800765917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27800765911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13900382958 + 13900382959.

It is an arithmetic number, because the mean of its divisors is an integer number (13900382959).

Almost surely, 2^27800765917 is an apocalyptic number.

It is an amenable number.

27800765917 is a deficient number, since it is larger than the sum of its proper divisors (1).

27800765917 is an equidigital number, since it uses as much as digits as its factorization.

27800765917 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1481760, while the sum is 52.

The spelling of 27800765917 in words is "twenty-seven billion, eight hundred million, seven hundred sixty-five thousand, nine hundred seventeen".