643272165 has 128 divisors (see below), whose sum is σ = 1269596160. Its totient is φ = 307929600.

The previous prime is 643272109. The next prime is 643272167. The reversal of 643272165 is 561272346.

643272165 is a `hidden beast` number, since 6 + 432 + 7 + 216 + 5 = 666.

It is not a de Polignac number, because 643272165 - 2⁶ = 643272101 is a prime.

Together with 626323995 it forms an amicable pair .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643272167) 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 in 127 ways as a sum of consecutive naturals, for example, 3946374 + ... + 3946536.

It is an arithmetic number, because the mean of its divisors is an integer number (9918720).

Almost surely, 2^643272165 is an apocalyptic number.

It is an amenable number.

643272165 is a deficient number, since it is larger than the sum of its proper divisors (626323995).

643272165 is a wasteful number, since it uses less digits than its factorization.

643272165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 272 (or 266 counting only the distinct ones).

The product of its digits is 60480, while the sum is 36.

The square root of 643272165 is about 25362.8106683782. The cubic root of 643272165 is about 863.2400604682.

The spelling of 643272165 in words is "six hundred forty-three million, two hundred seventy-two thousand, one hundred sixty-five".