27706206221 has 2 divisors, whose sum is σ = 27706206222. Its totient is φ = 27706206220.

The previous prime is 27706206139. The next prime is 27706206251. The reversal of 27706206221 is 12260260772.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27618783721 + 87422500 = 166189^2 + 9350^2 .

It is a cyclic number.

It is not a de Polignac number, because 27706206221 - 2²⁶ = 27639097357 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27706206251) 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, 13853103110 + 13853103111.

It is an arithmetic number, because the mean of its divisors is an integer number (13853103111).

Almost surely, 2^27706206221 is an apocalyptic number.

It is an amenable number.

27706206221 is a deficient number, since it is larger than the sum of its proper divisors (1).

27706206221 is an equidigital number, since it uses as much as digits as its factorization.

27706206221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28224, while the sum is 35.

Adding to 27706206221 its reverse (12260260772), we get a palindrome (39966466993).

The spelling of 27706206221 in words is "twenty-seven billion, seven hundred six million, two hundred six thousand, two hundred twenty-one".