999643domain: NAppears in sequencesNumbers k such that the sum of digits^4 of k equals Sum_{d|k, 1<d<k} d.at n=9A202147Numbers k such that sum of 4th power of digits of k equals the sum of prime divisors of k.at n=33A217532Numbers whose arithmetic derivative is equal to the sum of some fixed power of their digits.at n=31A269719