Properties of the Number 19951

Nineteen Thousand Nine Hundred Fifty-One

Basics

Value: 19950 → 19951 → 19952

Parity: odd

Prime: No

Previous Prime: 19949

Next Prime: 19961

Digit Sum: 25

Digital Root: 7

Palindrome: No

Factorization: 71 × 281

Divisors: 1, 71, 281, 19951

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100110111101111

Octal: 46757

Duodecimal: B667

Hexadecimal: 4def

Square: 398042401

Square Root: 141.24800883552305

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

Fermat pseudoprimes to base 2, also called Sarrus numbers or Poulet numbers. A1567

a(n) = a(n-1) + 7·a(n-2), a(0)=0, a(1)=1. A15442

Super-Poulet numbers: Poulet numbers whose divisors d all satisfy d∣2^d-2. A50217

Fermat pseudoprimes to base 2 with two prime factors. A214305

Strong pseudoprimes to base 4. A20230

Sarrus numbers A001567 that are not Carmichael numbers A002997. A153508

Pseudoprimes whose prime factors do not divide any smaller pseudoprime. A84653

Partial sums of A151791. A151792

Odd composite integers m such that A087130(m) == 5 (mod m). A335671

Odd composite integers m such that A052918(m-J(m,29)) == 0 (mod m) and gcd(m,29)=1, where J(m,29) is the Jacobi symbol. A340095