27981911 has 2 divisors, whose sum is σ = 27981912. Its totient is φ = 27981910.

The previous prime is 27981901. The next prime is 27981913. The reversal of 27981911 is 11918972.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27981911 is a prime.

Together with 27981913, 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 (27981913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13990955 + 13990956.

It is an arithmetic number, because the mean of its divisors is an integer number (13990956).

Almost surely, 2^27981911 is an apocalyptic number.

27981911 is a deficient number, since it is larger than the sum of its proper divisors (1).

27981911 is an equidigital number, since it uses as much as digits as its factorization.

27981911 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 38.

The square root of 27981911 is about 5289.7930961428. The cubic root of 27981911 is about 303.5934916032.

The spelling of 27981911 in words is "twenty-seven million, nine hundred eighty-one thousand, nine hundred eleven".