Properties of the Number 21769

Twenty-One Thousand Seven Hundred Sixty-Nine

Basics

Value: 21768 → 21769 → 21770

Parity: odd

Prime: No

Previous Prime: 21767

Next Prime: 21773

Digit Sum: 25

Digital Root: 7

Palindrome: No

Factorization: 11 × 1979

Divisors: 1, 11, 1979, 21769

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101010100001001

Octal: 52411

Duodecimal: 10721

Hexadecimal: 5509

Square: 473889361

Square Root: 147.54321400864222

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 nXk 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 1 or 3 neighboring 1s. A296396

a(0) = 12, after which, if (2·a(n-1)) - 1 = ∏_{k >= 1} (p_k)^c_k then a(n) = ∏_{k >= 1} (p_k-1)^c_k, where p_k indicates the k-th prime, A000040(k). A246343

Consecutive states of the linear congruential pseudo-random number generator (10924·s+11830) mod (2¹⁵+1) when started at s=1. A384150

Rectangular array A read by upward antidiagonals in which the entry in row n and column k is defined by A(n,k) = A254067(n,k) - A257499(n,k), n,k >= 1. A254131

Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 80 ones. A31848

Number of nX5 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 1 or 3 neighboring 1s. A296393

Records in A361321. A361325

a(n) = s(1)s(n) + s(2)s(n-1) + ... + s(k)s(n-k+1), where k = [ n/2 ], s = A000201 (lower Wythoff sequence). A25118

Number of n X n 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 1 or 3 neighboring 1's. A296389

Expansion of e.g.f. A(x) satisfying A(x/A(x)²) = exp(x·A(x)²). A368632