Properties of the Number 21100

Twenty-One Thousand One Hundred

Basics

Value: 21099 → 21100 → 21101

Parity: even

Prime: No

Previous Prime: 21089

Next Prime: 21101

Digit Sum: 4

Digital Root: 4

Palindrome: No

Factorization: 2 ² × 5 ² × 211

Divisors: 1, 2, 4, 5, 10, 20, 25, 50, 100, 211

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101001001101100

Octal: 51154

Duodecimal: 10264

Hexadecimal: 526c

Square: 445210000

Square Root: 145.2583904633395

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

Sum of squares of four consecutive primes. A133524

Multiples of 4 whose digits add to 4. A63997

29-gonal numbers: a(n) = n*(27·n-25)/2. A255187

Determinant of the n X n matrix with (i,j)-entry equal to 1 or 0 according as 2*(i + j) - 1 is prime or not. A228616

Negasemiternary (or NST) representation of n. A355904

Numbers of rank 11 in the poset of lunar numbers. A191753

Ternary numbers that are concatenated runs C(1)A(1)B(1)C(2)A(2)B(2)...C(k)A(k)B(k), where A(i) is a run of 1's, B(i) a run of 0's, and C(i) a run of 2's, for i = 1..k. A371111

Full Łukasiewicz word for each rooted plane tree (interpretation e in Stanley's exercise 19) encoded by A014486 (or A063171). A79436

Expansion of ∏_m>=1 (1 + q^m)²⁵. A22589

Sophie Germain 5-almost primes. A211162