664694271 has 48 divisors (see below), whose sum is σ = 1078552800. Its totient is φ = 391993344.

The previous prime is 664694213. The next prime is 664694287. The reversal of 664694271 is 172496466.

It is not a de Polignac number, because 664694271 - 2⁶ = 664694207 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664694201) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 397425 + ... + 399093.

It is an arithmetic number, because the mean of its divisors is an integer number (22469850).

Almost surely, 2^664694271 is an apocalyptic number.

664694271 is a deficient number, since it is larger than the sum of its proper divisors (413858529).

664694271 is a wasteful number, since it uses less digits than its factorization.

664694271 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1848 (or 1845 counting only the distinct ones).

The product of its digits is 435456, while the sum is 45.

The square root of 664694271 is about 25781.6654039261. The cubic root of 664694271 is about 872.7180905432.

The spelling of 664694271 in words is "six hundred sixty-four million, six hundred ninety-four thousand, two hundred seventy-one".