27747707681 has 2 divisors, whose sum is σ = 27747707682. Its totient is φ = 27747707680.

The previous prime is 27747707651. The next prime is 27747707699. The reversal of 27747707681 is 18670774772.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23667053281 + 4080654400 = 153841^2 + 63880^2 .

It is a cyclic number.

It is not a de Polignac number, because 27747707681 - 2¹⁴ = 27747691297 is a prime.

It is a super-2 number, since 2×27747707681² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (27747707651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13873853840 + 13873853841.

It is an arithmetic number, because the mean of its divisors is an integer number (13873853841).

Almost surely, 2^27747707681 is an apocalyptic number.

It is an amenable number.

27747707681 is a deficient number, since it is larger than the sum of its proper divisors (1).

27747707681 is an equidigital number, since it uses as much as digits as its factorization.

27747707681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6453888, while the sum is 56.

The spelling of 27747707681 in words is "twenty-seven billion, seven hundred forty-seven million, seven hundred seven thousand, six hundred eighty-one".