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  "body": "\n## Definition\n\nA positive integer $n$ is deficient if the sum of its positive divisors other than $n$ is less than $n$.\nEquivalently, $\\sigma(n) \u003c 2n$, where $\\sigma$ is the [[sum of divisors|009QCP5T3Z]].\n\n## Remarks\n\nEach prime $p$ is deficient, since its only smaller divisor is $1$.\nMore generally, each prime power is deficient. For example, $1 + 2 + 4 = 7 \u003c 8$.\nEach divisor of a deficient number or of a [[perfect number|0SB7Q8SYSF]], other than the number itself, is deficient.\n\n## Explanations\n\n### L1 human\n\nA deficient number has \"too few\" divisors: its smaller divisors add up to less than the number.\nMost small numbers are deficient, for example $1, 2, 3, 4, 5, 7, 8, 9, 10$.\n",
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