65991271 has 2 divisors, whose sum is σ = 65991272. Its totient is φ = 65991270.

The previous prime is 65991259. The next prime is 65991293. The reversal of 65991271 is 17219956.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 65991271 - 2⁷ = 65991143 is a prime.

It is a Chen prime.

It is equal to p_3895645 and since 65991271 and 3895645 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65991241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32995635 + 32995636.

It is an arithmetic number, because the mean of its divisors is an integer number (32995636).

Almost surely, 2^65991271 is an apocalyptic number.

65991271 is a deficient number, since it is larger than the sum of its proper divisors (1).

65991271 is an equidigital number, since it uses as much as digits as its factorization.

65991271 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34020, while the sum is 40.

The square root of 65991271 is about 8123.5011540591. The cubic root of 65991271 is about 404.1061851231.

The spelling of 65991271 in words is "sixty-five million, nine hundred ninety-one thousand, two hundred seventy-one".