2021

This number is a composite.

+ The smallest number that is the concatenation of two consecutive integers and also the product of two consecutive prime factors. See PC89107...70827 (36-digits). [Silva]

+ The only brilliant number concatenated from two successive double-digit numbers and the product of successive primes, i.e., 2021 = 43 * 47. [Loungrides]

+ The year "twenty twenty-one" hides a list of all three double-digit primes beginning with the digit four: 20 + 21 = 41 and 2021 = 43 * 47. [Leonardis]

+ The current semiprime year. [Jha]

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