Properties of the Number 18191

Eighteen Thousand One Hundred Ninety-One

Basics

Value: 18190 → 18191 → 18192

Parity: odd

Prime: Yes

Previous Prime: 18181

Next Prime: 18199

Digit Sum: 20

Digital Root: 2

Palindrome: No

Factorization: 18191

Divisors: 1, 18191

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 100011100001111

Octal: 43417

Duodecimal: A63B

Hexadecimal: 470f

Square: 330912481

Square Root: 134.87401528834232

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

Smallest prime p of form p = 8k-1 such that first n primes (p₁=2, ..., p_n) are quadratic residues mod p. A2223

Least negative pseudosquare modulo the first n odd primes. A45535

a(n) is the least number m such that the n-th prime is the least quadratic nonresidue modulo m. A229

Numbers whose least quadratic nonresidue (A020649) is 29. A25029

Total number of congruence subgroups of PSL(2,Z) of genus n. A258691

T(n,k)=Number of nXk 0..3 arrays with rows and columns lexicographically nondecreasing and every element equal to at least one horizontal or vertical neighbor. A201625

Primes having only {1, 8, 9} as digits. A385783

Smallest prime p such that the maximum run length of consecutive positive quadratic residues modulo p is n. A97159

Primes of the form 4·k-1 such that 8·k-1 and 16·k-1 are also primes. A101791

Records in A000229. A133435