27815987 has 2 divisors, whose sum is σ = 27815988. Its totient is φ = 27815986.

The previous prime is 27815941. The next prime is 27815989. The reversal of 27815987 is 78951872.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 27815987 - 2¹⁶ = 27750451 is a prime.

Together with 27815989, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (27815989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13907993 + 13907994.

It is an arithmetic number, because the mean of its divisors is an integer number (13907994).

Almost surely, 2^27815987 is an apocalyptic number.

27815987 is a deficient number, since it is larger than the sum of its proper divisors (1).

27815987 is an equidigital number, since it uses as much as digits as its factorization.

27815987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 282240, while the sum is 47.

The square root of 27815987 is about 5274.0863663766. The cubic root of 27815987 is about 302.9922300469.

The spelling of 27815987 in words is "twenty-seven million, eight hundred fifteen thousand, nine hundred eighty-seven".