Strange number 123456

To exclude I/O from this post I've modified code. So now it not only calculates factorials but also sums their digits and at last sums the sums of digits and as a result there's on one I/O operation. Lisp as usual behaving quite good. And a result of this code:

	(defun factorial (n)
	(defun i_factorial (k acc)
	(if (= 0 k)
	acc
	(i_factorial (- k 1) (* k acc))))
	(i_factorial n 1))
	(defun digits (n)
	(defun i_digits (k acc)
	(if (= 0 k)
	acc
	(i_digits (truncate k 10) (cons (mod k 10) acc))))
	(i_digits n '()))
	(defun digits_s (n)
	(mapcar
	#'(lambda (k) (parse-integer (string k)))
	(coerce (write-to-string n) 'list)))
	(format T "~D~%"
	(time (reduce
	'+
	(mapcar
	#'(lambda (n)
	(reduce
	'+
	(digits_s (factorial n))))
	'(1 12 123 1234 12345 123456)))))

view raw test.lisp hosted with ❤ by GitHub

is

Evaluation took:
  7.762 seconds of real time
  7.565354 seconds of total run time (7.363660 user, 0.201694 system)
  [ Run times consist of 0.399 seconds GC time, and 7.167 seconds non-GC time. ]
  97.46% CPU
  17,812,436,719 processor cycles
  177 page faults
  15,624,347,568 bytes consed
  
2652733

Almost similar results I've got from Go program:

	package main
	import (
	"fmt"
	"math/big"
	"strings"
	"strconv"
	"time"
	)
	func Factorial(n *big.Int) *big.Int {
	var unit = big.NewInt(1)
	var acc *big.Int = big.NewInt(1)
	var t = n
	for t.Cmp(unit) == 1 {
	acc.Mul(acc, t)
	t.Sub(t, unit)
	}
	return acc
	}
	func SumDigits(n string) int64 {
	var r int64
	l := strings.Split(n, "")
	for i := 0; i < len(l); i++ {
	d, _ := strconv.ParseInt(l[i], 10, 0)
	r += d
	}
	return r
	}
	func main() {
	var s int64 = 0
	t1 := time.Now()
	n := []int64{1, 12, 123, 1234, 12345, 123456}
	for i := 0; i < len(n); i++ {
	r := Factorial(big.NewInt(n[i]))
	s += SumDigits(r.String())
	}
	t2 := time.Now()
	fmt.Printf("Elapsed time: %v\n", t2.Sub(t1))
	fmt.Println(s)
	}

view raw test.go hosted with ❤ by GitHub

Elapsed time: 4.509443s
2652733

But strangely Clojure, Haskell and Julia have got some very strange behavior. Till 12345! everything seems to be ok (though for Clojure it takes almost 1.5 sec to calculate while Lisp done it in 0.091 seconds of real time). But when we get 123456! Clojure needs almost 1 minute, Haskell and Julia just plainly refused to calculate. Even in case of Julia it was not so plainly cause it decided to eat almost all memory.