Properties of the Number 1261

One Thousand Two Hundred Sixty-One

Basics

Value: 1260 → 1261 → 1262

Parity: odd

Prime: No

Previous Prime: 1259

Next Prime: 1277

Digit Sum: 10

Digital Root: 1

Palindrome: No

Factorization: 13 × 97

Divisors: 1, 13, 97, 1261

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10011101101

Octal: 2355

Duodecimal: 891

Hexadecimal: 4ed

Square: 1590121

Square Root: 35.510561809129406

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

Central polygonal numbers: a(n) = n² - n + 1. A2061

Hex (or centered hexagonal) numbers: 3·n*(n+1)+1 (crystal ball sequence for hexagonal lattice). A3215

a(n) = ∑_{d divides n} q(d), where q(d) = A000009 = number of partitions of d into distinct parts. A47966

Centered 12-gonal numbers, or centered dodecagonal numbers: numbers of the form 6·k*(k-1) + 1. A3154

Flavius Josephus's sieve: Start with the natural numbers; at the k-th sieving step, remove every (k+1)-st term of the sequence remaining after the (k-1)-st sieving step; iterate. A960

Partial sums of A000009 (partitions into distinct parts). A36469

Generalized Fibonacci numbers. A15441

Concentric hexagonal numbers: floor(3·n²/2). A32528

a(n) = 4·n² - 10·n + 7. A54554

Hexanacci numbers with a(0) = ... = a(5) = 1. A383