Properties of the Number 1965

One Thousand Nine Hundred Sixty-Five

Basics

Value: 1964 → 1965 → 1966

Parity: odd

Prime: No

Previous Prime: 1951

Next Prime: 1973

Digit Sum: 21

Digital Root: 3

Palindrome: No

Factorization: 3 × 5 × 131

Divisors: 1, 3, 5, 15, 131, 393, 655, 1965

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 11110101101

Octal: 3655

Duodecimal: 1179

Hexadecimal: 7ad

Square: 3861225

Square Root: 44.328320518603

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

Total number of parts in all partitions of n. Also, sum of largest parts of all partitions of n. A6128

Triangular matrix T, read by rows, where row n of T equals row (n-1) of Tⁿ⁺¹ with an appended '1'. A121412

D-toothpick sequence of the third kind starting with a single toothpick. A220500

Number of solutions to c(1)*prime(2)+...+c(2n)*prime(2n+1) = -2, where c(i) = +-1 for i > 1, c(1) = 1. A261059

Numbers k such that σ(k) = σ(k+13). A15883

Numbers k for which nontrivial positive magic squares of exactly 5 different orders with magic sum k exist. For a definition of nontrivial positive magic squares, see A125005. A125012

Sum of gcd(x, y) for 1 <= x, y <= n. A18806

Number of abelian/medial racks of order n, up to isomorphism. A383144

Numbers that have 7 terms in their Zeckendorf representation. A179247

Number of Look-and-Say partitions of n that are not section-sum partitions. A383509