Properties of the Number 1240

One Thousand Two Hundred Forty

Basics

Value: 1239 → 1240 → 1241

Parity: even

Prime: No

Previous Prime: 1237

Next Prime: 1249

Digit Sum: 7

Digital Root: 7

Palindrome: No

Factorization: 2 ³ × 5 × 31

Divisors: 1, 2, 4, 5, 8, 10, 20, 31, 40, 62

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2730 Try Today's Challenge

Representations

Binary: 10011011000

Octal: 2330

Duodecimal: 874

Hexadecimal: 4d8

Square: 1537600

Square Root: 35.21363372331802

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

Square pyramidal numbers: a(n) = 0² + 1² + 2² + ... + n² = n*(n+1)*(2·n+1)/6. A330

Generalized octagonal numbers: k*(3·k-2), k=0, +- 1, +- 2, +-3, ... A1082

a(n) = binomial(n+3, 3)/4 for odd n, n*(n+2)*(n+4)/24 for even n. A6918

Balanced numbers: numbers k such that φ(k) (A000010) divides σ(k) (A000203). A20492

Rhombic matchstick numbers: a(n) = n*(3·n+2). A45944

The "comma sequence": the lexicographically earliest sequence of positive numbers with the property that the sequence formed by the pairs of digits adjacent to the commas between the terms is the same as the sequence of successive differences between the terms. A121805

Number of 8-ary trees with n vertices. A7556

Number of partition into distinct parts (a₁, a₂, ... , a_m) (a₁ > a₂ > ... > a_m and ∑_k=1..m a_k = n) such that a1 - a2, a2 - a₃, ... , a_m-1 - a_m, a_m are different. A320348

Square array A(n,k), n>=0, k>=0, read by antidiagonals, where column k is Euler transform of (j->k). A144064

If A151873 is regarded as a triangle then the rows converge to this sequence. A151874