Properties of the Number 2642

Two Thousand Six Hundred Forty-Two

Basics

Value: 2641 → 2642 → 2643

Parity: even

Prime: No

Previous Prime: 2633

Next Prime: 2647

Digit Sum: 14

Digital Root: 5

Palindrome: No

Factorization: 2 × 1321

Divisors: 1, 2, 1321, 2642

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101001010010

Octal: 5122

Duodecimal: 1642

Hexadecimal: a52

Square: 6980164

Square Root: 51.40038910358559

Classification

Fibonacci: No

Bell Number: No

Factorial Number: No

Regular Number: No

Perfect Number: No

Special

Kaprekar Constant: No

Munchausen Constant: No

Armstrong Number: No

Kaprekar Number: No

Catalan Number: No

Vampire Number: No

Taxicab Number: No

Super Prime: No

Friedman Number: No

Fermat Number: No

Cullen Number: No

OEIS Sequences

Sum of first n semiprimes. A62198

A triangle formed like generalized Pascal's triangle. The rule is T(n,k) = 2·T(n-1,k-1) + T(n-1,k), the left border is n and the right border is n² instead of 1. A228576

Composite and every divisor (except for 1) contains the digit 2. A62664

Numbers k such that φ(k) = φ(k+2). A1494

Semiprimes sandwiched between semiprimes. A86005

T(n,k)=Number of (n+2)X(k+2) 0..1 arrays with every 3X3 subblock sum of the two medians of the diagonal and antidiagonal minus the sum of the minimums of the central row and column nondecreasing horizontally, vertically and ne-to-sw antidiagonally. A257189

Conjecturally largest even integer which is an unordered sum of two primes in exactly n ways. A954

Numbers k such that least prime in the Goldbach partition of k increases. A25018

a(n) = floor(π*n²). A66643

T(n,k)=Number of -k..k arrays x(0..n-1) of n elements with zero sum and no two neighbors equal. A199704