Properties of the Number 21697

Twenty-One Thousand Six Hundred Ninety-Seven

Basics

Value: 21696 → 21697 → 21698

Parity: odd

Prime: No

Previous Prime: 21683

Next Prime: 21701

Digit Sum: 25

Digital Root: 7

Palindrome: No

Factorization: 13 × 1669

Divisors: 1, 13, 1669, 21697

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101010011000001

Octal: 52301

Duodecimal: 10681

Hexadecimal: 54c1

Square: 470759809

Square Root: 147.29901561110313

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

T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with the minimum plus the maximum equal to the lower median plus the upper median in every 2X2 subblock. A235902

a(n) is the smallest number which can be represented as the sum of n distinct nonzero n-gonal numbers in exactly n ways, or 0 if no such number exists. A350405

Number of integer solutions to (x₁)² + (x₂)² + ... + (x₈)² <= n. A341397

a(n) = [xⁿ] theta₃(x)ⁿ/(1 - x), where theta₃() is the Jacobi θ function. A302860

a(n) = 288·n² - 168·n - 119. A118059

Number of lattice paths from (0,0) to (n,n) using Euclid's orchard as a step-set. A308087

Triangle read by rows: T(n,k) is the number of skew Dyck paths of semilength n and having k base pyramids. A129165

Number of skew Dyck paths of semilength n with no base pyramids. A129166

a(n) is the maximum integer for which some minimum-length sum equaling a(n) of perfect squares less than n² excludes (n-1)². A377084

Numbers k such that the continued fraction for sqrt(k) has period 99. A20438