Properties of the Number -121

One Hundred Twenty-One

Basics

Value: -122 → -121 → -120

Parity: odd

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 4

Digital Root: 4

Palindrome: Yes

Factorization: 11 ²

Divisors: 1, 11, 121

Polygonal

Triangular: No

Square: Yes

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: -1111001

Octal: -171

Duodecimal: -A1

Hexadecimal: -79

Square: 14641

Square Root: 11

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

Expansion of 1/(1 + x - x³ - x⁴ - x⁸ - x¹² - x¹³ - x¹⁷ - x²¹ - x²² - x²⁶ - x³⁰ - x³¹ + x³³ + x³⁴). A173908

Hafnian of a +/-1 array. A202038

Dirichlet inverse of the gcd-sum function (A018804). A101035

Coefficients of the '6th-order' mock θ function ψ(q). A53269

Determinant of the n X n (0,1)-matrix with (i,j)-entry equal to 1 if and only if i + j is 2 or an odd composite number. A228591

Nearest integer to n²*sin(n). A274087

a(n+1) = -∑_d∣n a(d), a(1) = 1. A281487

Expansion of exp( ∑_n>=1 -sigma₃(n)*xⁿ/n ) in powers of x. A283263

Alternating partial sums of A000217. A83392

Nearest integer to (n+1)*Bernoulli(n). A127187