Properties of the Number 20417

Twenty Thousand Four Hundred Seventeen

Basics

Value: 20416 → 20417 → 20418

Parity: odd

Prime: No

Previous Prime: 20411

Next Prime: 20431

Digit Sum: 14

Digital Root: 5

Palindrome: No

Factorization: 17 × 1201

Divisors: 1, 17, 1201, 20417

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100111111000001

Octal: 47701

Duodecimal: B995

Hexadecimal: 4fc1

Square: 416853889

Square Root: 142.88806808127822

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

Numerator of the n-th alternating harmonic number, ∑_k=1..n (-1)^k+1/k. A58313

Pseudoprimes to base 7. A5938

Number of strongly unimodal partitions of n (strongly unimodal means strictly increasing then strictly decreasing). A59618

Numerators of coefficients in power series for -log(1+x)*log(1-x). A49281

Let u(1) = x and u(n+1) = (n²/u(n)) + 1 for n >= 1; then a(n) is such that u(n) = (b(n)*x + c(n))/(a(n)*x + d(n)) (in lowest terms) and a(n), b(n), c(n), d(n) are positive integers. A75830

Euler pseudoprimes to base 7: composite integers such that abs(7^{(n - 1}/2)) == 1 mod n. A262054

Numerator of the product of n and the n-th alternating harmonic number, ∑_k=1..n (-1)^k+1/k. A119787

a(n) = (1/1 - 1/2 + ... + (-1)^n-1/n)*lcm{1..n}. A25530

Let u(1) = x and u(n+1) = (n²/u(n)) + 1 for n >= 1; then a(n) is such that u(n) =(a(n)*x + b(n))/(c(n)*x + d(n)) (in lowest terms) and a(n), b(n), c(n), d(n) are positive integers. A75827

Numbers k where the root mean square (RMS) of k and 7 is an integer, i.e., sqrt((k² + 7²)/2) is an integer. A76293