27666391 has 2 divisors, whose sum is σ = 27666392. Its totient is φ = 27666390.

The previous prime is 27666311. The next prime is 27666403. The reversal of 27666391 is 19366672.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 27666391 - 2¹⁵ = 27633623 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27666311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13833195 + 13833196.

It is an arithmetic number, because the mean of its divisors is an integer number (13833196).

Almost surely, 2^27666391 is an apocalyptic number.

27666391 is a deficient number, since it is larger than the sum of its proper divisors (1).

27666391 is an equidigital number, since it uses as much as digits as its factorization.

27666391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 81648, while the sum is 40.

The square root of 27666391 is about 5259.8850747901. The cubic root of 27666391 is about 302.4480834337.

The spelling of 27666391 in words is "twenty-seven million, six hundred sixty-six thousand, three hundred ninety-one".