643264317 has 6 divisors (see below), whose sum is σ = 929159582. Its totient is φ = 428842872.

The previous prime is 643264313. The next prime is 643264319. The reversal of 643264317 is 713462346.

It is a happy number.

643264317 is a `hidden beast` number, since 6 + 4 + 3 + 2 + 643 + 1 + 7 = 666.

It can be written as a sum of positive squares in only one way, i.e., 499120281 + 144144036 = 22341^2 + 12006^2 .

It is not a de Polignac number, because 643264317 - 2² = 643264313 is a prime.

It is a super-3 number, since 3×643264317³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643264313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35736898 + ... + 35736915.

Almost surely, 2^643264317 is an apocalyptic number.

It is an amenable number.

643264317 is a deficient number, since it is larger than the sum of its proper divisors (285895265).

643264317 is a wasteful number, since it uses less digits than its factorization.

643264317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71473819 (or 71473816 counting only the distinct ones).

The product of its digits is 72576, while the sum is 36.

The square root of 643264317 is about 25362.6559531923. The cubic root of 643264317 is about 863.2365499088.

The spelling of 643264317 in words is "six hundred forty-three million, two hundred sixty-four thousand, three hundred seventeen".