Properties of the Number 1521

One Thousand Five Hundred Twenty-One

Basics

Value: 1520 → 1521 → 1522

Parity: odd

Prime: No

Previous Prime: 1511

Next Prime: 1523

Digit Sum: 9

Digital Root: 9

Palindrome: No

Factorization: 3 ² × 13 ²

Divisors: 1, 3, 9, 13, 39, 117, 169, 507, 1521

Polygonal

Triangular: No

Square: Yes

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10111110001

Octal: 2761

Duodecimal: A69

Hexadecimal: 5f1

Square: 2313441

Square Root: 39

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

The squares: a(n) = n². A290

Perfect powers: m^k where m > 0 and k >= 2. A1597

Odd squares: a(n) = (2n+1)². Also centered octagonal numbers. A16754

Product of divisors of n. A7955

Number of rooted trees with n vertices in which vertices at the same level have the same degree. A3238

Powerful numbers (A001694) that are not prime powers (A000961). A286708

Perfect powers of nonprimes (m^k where m is a nonprime positive integer and k >= 2). A131605

Squarefree numbers squared. A62503

a(n) = ∑_k=1..n n/gcd(n,k). A57660

a(n) = n * ∏_{primes p∣n} p. A64549