Perfect digit-to-digit invariants
Encyclopedia
A perfect digit-to-digit invariant (PDDI) (also known as a Munchausen number) is a number that is equal to the sum of its digits
each raised to a power equal to the digit.
0 and 1 are PDDIs in any base (using the convention that 00 = 0). Apart from 0 and 1 there are only two other PDDIs in the decimal
system, 3435 and 438579088 .
More generally, there are finitely many PDDIs in any base.
Digit sum
In mathematics, the digit sum of a given integer is the sum of all its digits,...
each raised to a power equal to the digit.
0 and 1 are PDDIs in any base (using the convention that 00 = 0). Apart from 0 and 1 there are only two other PDDIs in the decimal
Decimal
The decimal numeral system has ten as its base. It is the numerical base most widely used by modern civilizations....
system, 3435 and 438579088 .
More generally, there are finitely many PDDIs in any base.