A natural number less than 200, each of its digits is an odd number, and it is the product of two two-digit numbers, then what is this natural number.
一个小于200的自然数，它的每位数字都是奇数，并且它是两个两位数的乘积，那么这个自然数是多少．
<gadget id="calculator">13 * 15</gadget>
<output>195</output>

<result>195</result>