643675 has 6 divisors (see below), whose sum is σ = 798188. Its totient is φ = 514920.

The previous prime is 643661. The next prime is 643681. The reversal of 643675 is 576346.

It is not a de Polignac number, because 643675 - 2⁷ = 643547 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12849 + ... + 12898.

2⁶⁴³⁶⁷⁵ is an apocalyptic number.

643675 is a deficient number, since it is larger than the sum of its proper divisors (154513).

643675 is a wasteful number, since it uses less digits than its factorization.

643675 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25757 (or 25752 counting only the distinct ones).

The product of its digits is 15120, while the sum is 31.

The square root of 643675 is about 802.2935871612. The cubic root of 643675 is about 86.3420217881.

It can be divided in two parts, 6 and 43675, that added together give a square (43681 = 209²).

The spelling of 643675 in words is "six hundred forty-three thousand, six hundred seventy-five".