27558523661 has 2 divisors, whose sum is σ = 27558523662. Its totient is φ = 27558523660.

The previous prime is 27558523621. The next prime is 27558523667. The reversal of 27558523661 is 16632585572.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27554008036 + 4515625 = 165994^2 + 2125^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27558523661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27558523667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13779261830 + 13779261831.

It is an arithmetic number, because the mean of its divisors is an integer number (13779261831).

Almost surely, 2^27558523661 is an apocalyptic number.

It is an amenable number.

27558523661 is a deficient number, since it is larger than the sum of its proper divisors (1).

27558523661 is an equidigital number, since it uses as much as digits as its factorization.

27558523661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3024000, while the sum is 50.

The spelling of 27558523661 in words is "twenty-seven billion, five hundred fifty-eight million, five hundred twenty-three thousand, six hundred sixty-one".