87991271 has 2 divisors, whose sum is σ = 87991272. Its totient is φ = 87991270.

The previous prime is 87991247. The next prime is 87991273. The reversal of 87991271 is 17219978.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 87991271 - 2¹⁸ = 87729127 is a prime.

Together with 87991273, 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 (87991273) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43995635 + 43995636.

It is an arithmetic number, because the mean of its divisors is an integer number (43995636).

Almost surely, 2^87991271 is an apocalyptic number.

87991271 is a deficient number, since it is larger than the sum of its proper divisors (1).

87991271 is an equidigital number, since it uses as much as digits as its factorization.

87991271 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 63504, while the sum is 44.

The square root of 87991271 is about 9380.3662508454. The cubic root of 87991271 is about 444.7813107168.

The spelling of 87991271 in words is "eighty-seven million, nine hundred ninety-one thousand, two hundred seventy-one".