Uniqueness conjecture for odd deficient perfect numbers with four distinct prime factors

An odd deficient perfect number is an odd positive integer whose proper-divisor sum is less than the number itself; it has four distinct prime factors when its prime factorization contains exactly four distinct primes. Uniqueness conjecture. There is only one odd deficient perfect number with four distinct prime factors. This conjecture is motivated by numerical evidence and concerns the unresolved classification of odd deficient perfect numbers with four distinct prime factors.