664271 has 2 divisors, whose sum is σ = 664272. Its totient is φ = 664270.

The previous prime is 664253. The next prime is 664273. The reversal of 664271 is 172466.

664271 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-664271 is a prime.

It is a super-2 number, since 2×664271² = 882511922882, which contains 22 as substring.

Together with 664273, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 664271.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664273) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332135 + 332136.

It is an arithmetic number, because the mean of its divisors is an integer number (332136).

2⁶⁶⁴²⁷¹ is an apocalyptic number.

664271 is a deficient number, since it is larger than the sum of its proper divisors (1).

664271 is an equidigital number, since it uses as much as digits as its factorization.

664271 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2016, while the sum is 26.

The square root of 664271 is about 815.0282203703. The cubic root of 664271 is about 87.2532805011.

The spelling of 664271 in words is "six hundred sixty-four thousand, two hundred seventy-one".