Implicit conversion of a 32-bit unsigned integer (UInt) to a Decimal requires you to first declare a UInt.
uint val = 342741539;
Now to convert it to decimal, just assign the value.
decimal dec; // implicit dec = val;
Example
using System;
public class Demo {
public static void Main() {
uint val = 342741539;
decimal dec;
// implicit
dec = val;
Console.WriteLine("Decimal = "+dec);
}
}Output
Decimal = 342741539