4×161

4×161 is the product of the integers 4 and 161. Calculating the product yields 644, since 161×4 = 644. A quick breakdown shows 644 = 400 + 240 + 4.

Prime factorization and divisors: 161 factors as 7×23, so 644 = 2^2 × 7 × 23. This makes 644 a composite number with 12 positive divisors: 1, 2, 4, 7, 14, 28, 23, 46, 92, 161, 322, and 644.

Representations in other bases: in binary, 644 is 1010000100_2 (as 512 + 128 + 4 = 644). In hexadecimal, 644 equals 0x284. In octal, it is 1204_8.

Context and relevance: The expression 4×161 is a straightforward example of multiplying a small integer by a two-digit integer, illustrating simple arithmetic and the resulting factorization. It also demonstrates how the product’s prime factorization derives from the factors involved. The number 644 itself appears in various counting or measurement contexts where multiples of 4 and of 161 might arise.

See also: multiplication, prime factorization, base-related numeral systems.

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