Properties of the Number 1911

One Thousand Nine Hundred Eleven

Basics

Value: 1910 → 1911 → 1912

Parity: odd

Prime: No

Previous Prime: 1907

Next Prime: 1913

Digit Sum: 12

Digital Root: 3

Palindrome: No

Factorization: 3 × 7 ² × 13

Divisors: 1, 3, 7, 13, 21, 39, 49, 91, 147, 273

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

4823 Try Today's Challenge

Representations

Binary: 11101110111

Octal: 3567

Duodecimal: 1133

Hexadecimal: 777

Square: 3651921

Square Root: 43.71498598878879

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

a(n) = sigma₂(n): sum of squares of divisors of n. A1157

11-gonal (or hendecagonal) numbers: a(n) = n*(9·n-7)/2. A51682

a(n) = ∑_k=1..n n/gcd(n,k). A57660

Numbers > 1000 such that all the substrings of length = 3 are primes (substrings with leading '0' are considered to be nonprime). A211684

Generalized 11-gonal (or hendecagonal) numbers: m*(9·m - 7)/2 with m = 0, 1, -1, 2, -2, 3, -3, ... A195160

Heptagonal (or 7-gonal) pyramidal numbers: a(n) = n*(n+1)*(5·n-2)/6. A2413

V-toothpick (or honeycomb) sequence (see Comments lines for definition). A161206

Numbers whose base-16 expansion has no run of digits with length < 2. A33029

Number of incomplete integer partitions of n, meaning not every number from 0 to n is the sum of some submultiset. A365924

Powers of cube root of 17 rounded to nearest integer. A18025