175

Raising the decimal digits of 175 to the powers of successive integers produces 175 back again: 175 = 11 + 72 + 53. 175 is a figurate number for a rhombic dodecahedron, the difference of two consecutive fourth powers: 175 = 44 − 34. It is also a decagonal number and a decagonal pyramid number, the smallest number after 1 that has both properties.