Properties of the Number 87990

Eighty-Seven Thousand Nine Hundred Ninety

Basics

Value: 87989 → 87990 → 87991

Parity: even

Prime: No

Previous Prime: 87977

Next Prime: 87991

Digit Sum: 33

Digital Root: 6

Palindrome: No

Factorization: 2 × 3 × 5 × 7 × 419

Divisors: 1, 2, 3, 5, 6, 7, 10, 14, 15, 21

Polygonal

Triangular: Yes

Square: No

Pentagonal: No

Hexagonal: Yes

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 10101011110110110

Octal: 253666

Duodecimal: 42B06

Hexadecimal: 157b6

Square: 7742240100

Square Root: 296.6310840084026

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

a(n) = n⁴ - (n-1)⁴ + (n-2)⁴ - ... 0⁴. A62392

The first of three consecutive triangular numbers the sum of which is equal to the sum of three consecutive primes. A298168

Triangle T(n,k) in which n-th row lists the values of the n-th derivative at x=1 of all functions that are representable as x^x^...^x with n x's and parentheses inserted in all possible ways; n>=1, 1<=k<=A000081(n). A216349

Triangle T(n,k) in which n-th row lists in increasing order the values of the n-th derivative at x=1 of all functions that are representable as x^x^...^x with n x's and parentheses inserted in all possible ways; n>=1, 1<=k<=A000081(n). A216350

n-th derivative of x^{x^(n-1}) at x=1. A216351

Even triangular numbers with prime indices. A34955

Sixth derivative of f_n at x=1, where f_n is the n-th of all functions that are representable as x^x^...^x with m>=1 x's and parentheses inserted in all possible ways. A215836

Triangular arithmetic on half-squares: b(n)*(b(n) - 1)/2 where b(n) = floor(n²/2). A227970

a(n) = [ a(n-1)/a(1) + a(n-3)/a(3) + a(n-5)/a(5) + ... ], for n >= 3. A22871

a(1) = 0, then smallest triangular number such that a(n+1)- a(n) is a palindrome. A75057