Properties of the Number 9801

Nine Thousand Eight Hundred One

Basics

Value: 9800 → 9801 → 9802

Parity: odd

Prime: No

Previous Prime: 9791

Next Prime: 9803

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 3 ⁴ × 11 ²

Divisors: 1, 3, 9, 11, 27, 33, 81, 99, 121, 297

Polygonal

Triangular: No

Square: Yes

Pentagonal: Yes

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10011001001001

Octal: 23111

Duodecimal: 5809

Hexadecimal: 2649

Square: 96059601

Square Root: 99

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: Yes

Catalan Number: No

Vampire Number: No

Taxicab Number: No

Super Prime: No

Friedman Number: No

Fermat Number: No

Cullen Number: No

OEIS Sequences

a(n) = period of the sequence {b(m), m>=0}, defined by b(m):=binomial(m+n,n) mod n. A133900

a(n) and floor(a(n)/2) are both squares; i.e., squares which remain squares when written in base 2 and last digit is removed. A55792

Take solution to Pellian equation x² - n·y² = 1 with smallest positive y and x >= 0; sequence gives a(n) = x, or 1 if n is a square. A002349 gives values of y. A2350

Perfect powers of nonsquarefree numbers k that are not squareful. A386762

a(n) = a(n-1) + a(n - 1 - number of even terms so far). A6336

Smallest positive integer·satisfying the Pell equation x² - D·y² = 1 for nonsquare D and positive y. A33313

a(n) = (3·n)². A16766

a(n) = floor( a(n-1)/(sqrt(2) - 1) ), with a(0) = 1. A24537

Numbers of the form 3ⁱ*11^j. A3597

Nontrivial reversal numbers (numbers which are integer multiples of their reversals), excluding palindromic numbers and multiples of 10. A31877