Properties of the Number 1815

One Thousand Eight Hundred Fifteen

Basics

Value: 1814 → 1815 → 1816

Parity: odd

Prime: No

Previous Prime: 1811

Next Prime: 1823

Digit Sum: 15

Digital Root: 6

Palindrome: No

Factorization: 3 × 5 × 11 ²

Divisors: 1, 3, 5, 11, 15, 33, 55, 121, 165, 363

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2730 Try Today's Challenge

Representations

Binary: 11100010111

Octal: 3427

Duodecimal: 1073

Hexadecimal: 717

Square: 3294225

Square Root: 42.60281680828159

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

Number of partitions of n into at least two distinct parts. A111133

Number of sets (in the Hausdorff metric geometry) at each location between two sets defining a polygonal configuration consisting of k 4-gonal polygonal components chained with string components of length 1 as k varies. A152927

a(n) = 2ⁿ - Fibonacci(n+2). A8466

Multiples of 15 containing a 15 in their decimal representation. A121035

Number of integer partitions of n whose multiplicities cover an initial interval of positive integers. A317081

Triangle T(n,k) (n >= 2, k = 3..n+floor(n/2)) giving number of bicoverings of an n-set with k blocks. A59443

Bisection of A001400. A14125

Numbers m such that there are precisely 9 groups of order m. A249552

a(n) = A005940(1+(1+(3·A156552(n)))) = (1/2) * A005940(1+(3·A156552(2·n))). A329603

4-dimensional figurate numbers: a(n) = (5·n-1)*binomial(n+2,3)/4. A2418