27720191 has 2 divisors, whose sum is σ = 27720192. Its totient is φ = 27720190.

The previous prime is 27720167. The next prime is 27720193. The reversal of 27720191 is 19102772.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 27720191 - 2¹⁸ = 27458047 is a prime.

Together with 27720193, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27720193) 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, 13860095 + 13860096.

It is an arithmetic number, because the mean of its divisors is an integer number (13860096).

Almost surely, 2^27720191 is an apocalyptic number.

27720191 is a deficient number, since it is larger than the sum of its proper divisors (1).

27720191 is an equidigital number, since it uses as much as digits as its factorization.

27720191 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1764, while the sum is 29.

The square root of 27720191 is about 5264.9967711291. The cubic root of 27720191 is about 302.6440031083.

The spelling of 27720191 in words is "twenty-seven million, seven hundred twenty thousand, one hundred ninety-one".