It carries 1 MB of Flash and 256K x 8 of SRAM, which is enough to hold a full application image plus a moderate OTA staging buffer without external memory. The 140 I/O pins break out through a 176-LQFP package, giving you room for a parallel LCD, an external bus interface, and a bank of sensors or actuators.
There are also I²C, SPI, UART/USART, I²S, and IrDA interfaces for sensor arrays, audio codecs, and industrial fieldbuses.
The base product number is STM32F427, and the device is ROHS3 compliant. For production programs, this means no imminent last-time-buy risk.