27768687857 has 2 divisors, whose sum is σ = 27768687858. Its totient is φ = 27768687856.

The previous prime is 27768687847. The next prime is 27768687889. The reversal of 27768687857 is 75878686772.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27330371761 + 438316096 = 165319^2 + 20936^2 .

It is a cyclic number.

It is not a de Polignac number, because 27768687857 - 2¹⁰ = 27768686833 is a prime.

It is a super-2 number, since 2×27768687857² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (27768687847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13884343928 + 13884343929.

It is an arithmetic number, because the mean of its divisors is an integer number (13884343929).

Almost surely, 2^27768687857 is an apocalyptic number.

It is an amenable number.

27768687857 is a deficient number, since it is larger than the sum of its proper divisors (1).

27768687857 is an equidigital number, since it uses as much as digits as its factorization.

27768687857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 442552320, while the sum is 71.

The spelling of 27768687857 in words is "twenty-seven billion, seven hundred sixty-eight million, six hundred eighty-seven thousand, eight hundred fifty-seven".