Properties of the Number 19984

Nineteen Thousand Nine Hundred Eighty-Four

Basics

Value: 19983 → 19984 → 19985

Parity: even

Prime: No

Previous Prime: 19979

Next Prime: 19991

Digit Sum: 31

Digital Root: 4

Palindrome: No

Factorization: 2 ⁴ × 1249

Divisors: 1, 2, 4, 8, 16, 1249, 2498, 4996, 9992, 19984

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 100111000010000

Octal: 47020

Duodecimal: B694

Hexadecimal: 4e10

Square: 399360256

Square Root: 141.36477637657833

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

Starts of runs of 3 consecutive positive negaFibonacci-Niven numbers (A331085). A331087

Number of ways 1/n can be expressed as the sum of four distinct unit fractions: 1/n = 1/w + 1/x + 1/y + 1/z satisfying 0 < w < x < y < z. A241883

Sum of the prime parts in the partitions of n into 8 parts. A309469

Numbers n such that the digits of n end in φ(n). A67206

Positions of zeros in A345055, which is the Dirichlet inverse of A011772. A345053

Numbers n such that φ(n) is a proper substring of n. A66663

a(n) = 8·a(n-1) - 14·a(n-2) for n > 1; a(0) = 3, a(1) = 20. A164535

Triangle of coefficients of polynomials u(n,x) jointly generated with A208930; see the Formula section. A208909

Composite numbers n such that n - φ(n) is a power of 10. A248857

Becomes prime or 4 after exactly 9 iterations of f(x) = sum of prime factors of x. A48131