27997591 has 2 divisors, whose sum is σ = 27997592. Its totient is φ = 27997590.

The previous prime is 27997579. The next prime is 27997633. The reversal of 27997591 is 19579972.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 27997591 - 2⁵ = 27997559 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27997511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13998795 + 13998796.

It is an arithmetic number, because the mean of its divisors is an integer number (13998796).

Almost surely, 2^27997591 is an apocalyptic number.

27997591 is a deficient number, since it is larger than the sum of its proper divisors (1).

27997591 is an equidigital number, since it uses as much as digits as its factorization.

27997591 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 357210, while the sum is 49.

The square root of 27997591 is about 5291.2749881290. The cubic root of 27997591 is about 303.6501884344.

The spelling of 27997591 in words is "twenty-seven million, nine hundred ninety-seven thousand, five hundred ninety-one".