Use sprintf():
int someInt = 368;
char str[12];
sprintf(str, "%d", someInt);
All numbers that are representable by int will fit in a 12-char-array without overflow, unless your compiler is somehow using more than 32-bits for int. When using numbers with greater bitsize, e.g. long with most 64-bit compilers, you need to increase the array sizeāat least 21 characters for 64-bit types.