27399991 has 2 divisors, whose sum is σ = 27399992. Its totient is φ = 27399990.

The previous prime is 27399989. The next prime is 27400003. The reversal of 27399991 is 19999372.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 27399991 - 2¹ = 27399989 is a prime.

Together with 27399989, it forms a pair of twin primes.

It is the 5235-th Hogben number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27399941) by changing a digit.

It is a nontrivial repunit in base 5234.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13699995 + 13699996.

It is an arithmetic number, because the mean of its divisors is an integer number (13699996).

Almost surely, 2^27399991 is an apocalyptic number.

27399991 is a deficient number, since it is larger than the sum of its proper divisors (1).

27399991 is an equidigital number, since it uses as much as digits as its factorization.

27399991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 275562, while the sum is 49.

The square root of 27399991 is about 5234.5000716401. The cubic root of 27399991 is about 301.4741921407.

The spelling of 27399991 in words is "twenty-seven million, three hundred ninety-nine thousand, nine hundred ninety-one".