NAME
    factor - smallest prime factor not exceeding specified limit

SYNOPSIS
    factor(n [, limit [, err]])

TYPES
    n		integer
    limit	integer with abs(limit) < 2^32, defaults to 2^32 - 1
    err		integer

    return	positive integer, -1 or err

DESCRIPTION

    If n >= 0 and n has a prime factor less than or equal to limit,
    factor(n, limit) returns the smallest such factor.  If n >= 0
    and the smallest prime factor of n exceeds limit, 1 is returned.
    In particular, if n >= 0 and limit <= 1, factor(n, limit)
    always returns 1; factor(n,2) returns 2 if and only if n is even.

    If n < 0, -1 is returned.

    If abs(limit) >= 2^32, factor(n, limit) causes an error,
    factor(n, limit, err) returns the value of err.

EXAMPLE
    > print factor(35,4), factor(35,5), factor(35), factor(-35)
    1 5 5 -1

    > print factor(2^32 + 1), factor(2^47 - 1), factor(2^59 - 1)
    641 2351 179951

LIMITS
     none

LIBRARY
     FLAG zfactor(ZVALUE n, ZVALUE limit, ZVALUE *res)

SEE ALSO
    lfactor