Arduino for STM32

Hi, I have a question, about using 64-bit lenght data types. I'm using Arduino IDE (1.8.19), and if I put a declaration like this: uint64 bigNumber=0; it is compiling, but if I have: unsigned int number1=0; uint64 bigNumber=0; uint64_t number2=0; void setup() { Serial.begin(9600); } void loop() { bi...