Digit Product Calculator

How it is calculated

Enter a whole number. The tool reads the digits exactly as you typed them and multiplies them together: product = d₁ × d₂ × … × dₙ. It reports two results, the digit product and the number of digits. Any 0 digit makes the whole product 0. The sign is ignored, so -429 is treated as 429; leading zeros are dropped (007 is one digit), and the number 0 has one digit and a product of 0. Because the digit string is used directly, long numbers such as 20-digit IDs are handled exactly. A number with a fractional part, such as 4.29, shows no result, and so does a number whose product would exceed 9,007,199,254,740,992 (for example seventeen 9s), since larger products cannot be printed exactly.

Common mistakes

• Confusing digit product with digit sum. For 429 the sum is 15 but the product is 72.
• Forgetting that a 0 anywhere in the number gives a product of 0, which says nothing about the other digits.
• Typing a decimal such as 4.29 and expecting the digits after the point to count. The tool only accepts whole numbers, so a fractional value gives no result.
• Expecting a result for a long number made of large digits. Seventeen 9s would give a product above 9 quadrillion, so no result is shown, while a long number containing a 0 simply gives 0.
• Counting leading zeros. A value typed as 007 is the number 7: one digit, product 7.