Properties of the Number -397

Three Hundred Ninety-Seven

Basics

Value: -398 → -397 → -396

Parity: odd

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 397

Divisors: 1, 397

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: -110001101

Octal: -615

Duodecimal: -291

Hexadecimal: -18d

Square: 157609

Square Root: 19.924858845171276

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-x-x^N)/((1-x)(1-x²)(1-x³)...(1-x^N)) for N = 5. A60024

Partial alternating sums of Pillai's arithmetical function (A018804). A370895

a(n) = -a(n-2) - a(n-3). A112455

a(n) = 36·n² - 810·n + 2753, producing the conjectured record number of 45 primes in a contiguous range of n for quadratic polynomials, i.e., abs(a(n)) is prime for 0 <= n < 44. A117081

McKay-Thompson series of class 36e for the Monster group. A112175

Expansion of ∏_k>=1 (1 - x^k)^k*(k+1/2). A292386

Difference 2·k - A003961(k) computed for k for which this difference divides difference (A003961(k)-σ(k)), where A003961 is fully multiplicative with a(prime(i)) = prime(i+1). A379216

Expansion of f(-x¹, -x⁷) * f(-x², -x⁶) / (f(-x³, -x⁵) * f(-x⁴, -x⁴)) in powers of·where f(, ) is Ramanujan's general θ function. A226559

For 1<=x<=n, 1<=y<=n, with gcd(x,y)=1, write 1 = gcd(x,y) = u·x+v·y with u,v minimal; a(n) = sum of the values of u+v. A345425

a(n) = ∑_k=1..n (-1)^k-1 * binomial(k+1,2) * floor(n/k). A366937