Properties of the Number 2121

Two Thousand One Hundred Twenty-One

Basics

Value: 2120 → 2121 → 2122

Parity: odd

Prime: No

Previous Prime: 2113

Next Prime: 2129

Digit Sum: 6

Digital Root: 6

Palindrome: No

Factorization: 3 × 7 × 101

Divisors: 1, 3, 7, 21, 101, 303, 707, 2121

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2730 Try Today's Challenge

Representations

Binary: 100001001001

Octal: 4111

Duodecimal: 1289

Hexadecimal: 849

Square: 4498641

Square Root: 46.05431575867782

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

Numbers that contain only 1's and 2's. Nonempty binary strings of length n in lexicographic order. A7931

Doublets: base-10 representation is the juxtaposition of two identical strings. A20338

Generalized 12-gonal numbers: k*(5·k-4) for k = 0, +-1, +-2, ... A195162

12-gonal (or dodecagonal) numbers: a(n) = n*(5·n-4). A51624

Number of points of norm <= n² in square lattice. A328

a(n) is the least k such that 4^k mod k = n. A119678

Number of partitions of n such that the number of parts is divisible by the greatest part. Also number of partitions of n such that the greatest part is divisible by the number of parts. A168659

n written in fractional base 3/2. A24629

Interprimes (A024675) which are of the form s·prime, s=21. A75296

Number of finite languages over a binary alphabet (set of nonempty binary words of total length n). A102866