643504 has 20 divisors (see below), whose sum is σ = 1281664. Its totient is φ = 312768.

The previous prime is 643493. The next prime is 643507. The reversal of 643504 is 405346.

It is not an unprimeable number, because it can be changed into a prime (643507) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49 + ... + 1135.

2⁶⁴³⁵⁰⁴ is an apocalyptic number.

It is an amenable number.

643504 is a deficient number, since it is larger than the sum of its proper divisors (638160).

643504 is a wasteful number, since it uses less digits than its factorization.

643504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1132 (or 1126 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 22.

The square root of 643504 is about 802.1870106154. The cubic root of 643504 is about 86.3343751789.

The spelling of 643504 in words is "six hundred forty-three thousand, five hundred four".