27728761457 has 2 divisors, whose sum is σ = 27728761458. Its totient is φ = 27728761456.

The previous prime is 27728761453. The next prime is 27728761471. The reversal of 27728761457 is 75416782772.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26515562896 + 1213198561 = 162836^2 + 34831^2 .

It is a cyclic number.

It is not a de Polignac number, because 27728761457 - 2² = 27728761453 is a prime.

It is not a weakly prime, because it can be changed into another prime (27728761453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13864380728 + 13864380729.

It is an arithmetic number, because the mean of its divisors is an integer number (13864380729).

Almost surely, 2^27728761457 is an apocalyptic number.

It is an amenable number.

27728761457 is a deficient number, since it is larger than the sum of its proper divisors (1).

27728761457 is an equidigital number, since it uses as much as digits as its factorization.

27728761457 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9219840, while the sum is 56.

The spelling of 27728761457 in words is "twenty-seven billion, seven hundred twenty-eight million, seven hundred sixty-one thousand, four hundred fifty-seven".