Properties of the Number 19825

Nineteen Thousand Eight Hundred Twenty-Five

Basics

Value: 19824 → 19825 → 19826

Parity: odd

Prime: No

Previous Prime: 19819

Next Prime: 19841

Digit Sum: 25

Digital Root: 7

Palindrome: No

Factorization: 5 ² × 13 × 61

Divisors: 1, 5, 13, 25, 61, 65, 305, 325, 793, 1525

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 100110101110001

Octal: 46561

Duodecimal: B581

Hexadecimal: 4d71

Square: 393030625

Square Root: 140.80127840328723

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 k such that k!!-4 is prime. A123910

a(n) = ∑_k=0..n-1 binomial(n,k+1) * binomial(n+k,k). A2002

Numbers m that are the hypotenuse of exactly 22 distinct integer-sided right triangles, i.e., m² can be written as a sum of two squares in 22 ways. A97103

a(n) = T([n/2],[(n+1)/2]), where T = Delannoy triangle (A008288). A26003

Crystal ball sequence for 7-dimensional cubic lattice. A1849

Number triangle, equal to half of Delannoy square array A008288. A113139

Crystal ball sequence for 6-dimensional cubic lattice. A1848

a(n) = n*(n + 11)*(n + 22)/6. A264445

Numbers that are the sum of 2 nonzero squares in 5 or more ways. A25296

E.g.f.: (1/(1-x⁵))*exp( 5*∑_i>=0 x^5·i+1/(5·i+1) ) for an order-5 linear recurrence with varying coefficients. A97680