643586 has 16 divisors (see below), whose sum is σ = 1067904. Its totient is φ = 289344.

The previous prime is 643583. The next prime is 643589. The reversal of 643586 is 685346.

It is an interprime number because it is at equal distance from previous prime (643583) and next prime (643589).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (643583) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 371 + ... + 1193.

It is an arithmetic number, because the mean of its divisors is an integer number (66744).

2⁶⁴³⁵⁸⁶ is an apocalyptic number.

643586 is a deficient number, since it is larger than the sum of its proper divisors (424318).

643586 is a wasteful number, since it uses less digits than its factorization.

643586 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 865.

The product of its digits is 17280, while the sum is 32.

The square root of 643586 is about 802.2381192639. The cubic root of 643586 is about 86.3380421430.

The spelling of 643586 in words is "six hundred forty-three thousand, five hundred eighty-six".