Properties of the Number 1845

One Thousand Eight Hundred Forty-Five

Basics

Value: 1844 → 1845 → 1846

Parity: odd

Prime: No

Previous Prime: 1831

Next Prime: 1847

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 3 ² × 5 × 41

Divisors: 1, 3, 5, 9, 15, 41, 45, 123, 205, 369

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 11100110101

Octal: 3465

Duodecimal: 1099

Hexadecimal: 735

Square: 3404025

Square Root: 42.95346318982906

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) = n² - 4. A28347

Numerator of 1/4 - 1/n². A61037

Numbers that are the sum of 11 positive 6th powers. A3367

a(n) = n*(n + 1)*(5·n - 4)/2. A237616

Numbers that can be expressed as the difference of the squares of primes in just one distinct way. A90781

Number of partitions of n in which the greatest part is 9. A26815

a(n) = 4·a(n-1) - a(n-2) + 1, with a(0) = 0, a(1) = 2. A1571

a(0) = 0, a(1) = 1; a(n) = max { 4·a(k) + a(n-k) | 1 <= k <= n/2 }, for n > 1. A116520

Total sum T(n,k) of the sizes of all blocks with maximal element k in all set partitions of {1,2,...,n}; triangle T(n,k), n>=1, 1<=k<=n, read by rows. A270701

Total sum T(n,k) of the sizes of all blocks with minimal element k in all set partitions of {1,2,...,n}; triangle T(n,k), n>=1, 1<=k<=n, read by rows. A270702