Properties of the Number 9871

Nine Thousand Eight Hundred Seventy-One

Basics

Value: 9870 → 9871 → 9872

Parity: odd

Prime: Yes

Previous Prime: 9859

Next Prime: 9883

Digit Sum: 25

Digital Root: 7

Palindrome: No

Factorization: 9871

Divisors: 1, 9871

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10011010001111

Octal: 23217

Duodecimal: 5867

Hexadecimal: 268f

Square: 97436641

Square Root: 99.3529063490344

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

Primes of the form k(k+1)/2+1 (i.e., central polygonal numbers, or one more than triangular numbers). A55469

Primes of the form 210n + 1. A73102

a(n) = ceiling(∑_i=1..n-1 a(i)/4) for n >= 2 starting with a(1) = 1. A120160

a(n) = 8·n² + 2·n + 1. A188135

Largest prime with n distinct decimal digits. A7810

a(n) is the greatest prime > a(n-1) obtained by inserting a single digit anywhere in its string of digits (including at the beginning or end), starting with a(1) = 1. A389721

E.g.f. satisfies A(x) = exp(x·A(x²)). A138292

Primes that are the first in a run of exactly 2 emirps. A346022

Largest n-digit prime with strictly decreasing digits. A71361

Largest n-digit norep emirp. A30540