27660013861 has 2 divisors, whose sum is σ = 27660013862. Its totient is φ = 27660013860.

The previous prime is 27660013859. The next prime is 27660013939. The reversal of 27660013861 is 16831006672.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25446311361 + 2213702500 = 159519^2 + 47050^2 .

It is a cyclic number.

It is not a de Polignac number, because 27660013861 - 2¹ = 27660013859 is a prime.

Together with 27660013859, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27660013811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13830006930 + 13830006931.

It is an arithmetic number, because the mean of its divisors is an integer number (13830006931).

Almost surely, 2^27660013861 is an apocalyptic number.

It is an amenable number.

27660013861 is a deficient number, since it is larger than the sum of its proper divisors (1).

27660013861 is an equidigital number, since it uses as much as digits as its factorization.

27660013861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72576, while the sum is 40.

The spelling of 27660013861 in words is "twenty-seven billion, six hundred sixty million, thirteen thousand, eight hundred sixty-one".