Properties of the Number 42121

Forty-Two Thousand One Hundred Twenty-One

Basics

Value: 42120 → 42121 → 42122

Parity: odd

Prime: No

Previous Prime: 42101

Next Prime: 42131

Digit Sum: 10

Digital Root: 1

Palindrome: No

Factorization: 73 × 577

Divisors: 1, 73, 577, 42121

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 1010010010001001

Octal: 122211

Duodecimal: 20461

Hexadecimal: a489

Square: 1774178641

Square Root: 205.23401277566055

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

Composite numbers k of the form 4u+1 for which the odd part of φ(k) divides k-1. A339870

Numbers k such that -3 is a quadratic residue (not necessarily coprime) modulo k, k + 1, k + 2 and k + 3. A318527

Strong pseudoprimes to base 24. A20250

Strong pseudoprimes to base 38. A20264

Strong pseudoprimes to base 54. A20280

Expansion of f(-x)¹¹ / f(-x³) + 27·x * f(-x³)¹¹ / f(-x) in powers of·where f() is a Ramanujan θ function. A258724

Numbers n such that φ(n) = 4*φ(n-1). A268126

Numbers k such that 3^k-1 == 2^k-1 ≠= 1 (mod k). A285300

Least number k such that the concatenation of n consecutive numbers from k to k+n-1 is divisible by their sum. A375728

Number of (2,0)-separable partitions of n; see Comments. A239482