Example image of eyePlorer eyePlorer map for 'Perfect number': Divisor Negative and non-negative numbers Divisor function 28 (number) 6 (number) 496 (number) 8128 (number) Greek mathematics Euclid Prime number Marin Mersenne Mersenne prime Number theory Alhazen Leonhard Euler Infinite set Great Internet Mersenne Prime Search Hexagonal number Triangular number Carl Pomerance Heuristic algorithm Harmonic divisor number Modular arithmetic James Joseph Sylvester Richard K. Guy Strong Law of Small Numbers Multiplicative inverse Polite number Fermat number Abundant number Deficient number Numerology Amicable number Sociable number Practical number Aliquot sequence Definition Fixed point (mathematics) Sequence Euclid's Elements Mathematics of Computation List of perfect numbers Multiply perfect number Sublime number Hyperperfect number Jacques Touchard June 28 Pentalogy Semiperfect number Simon Davis (mathematician)