Properties of the Number 78121

Seventy-Eight Thousand One Hundred Twenty-One

Basics

Value: 78120 → 78121 → 78122

Parity: odd

Prime: Yes

Previous Prime: 78101

Next Prime: 78137

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 78121

Divisors: 1, 78121

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10011000100101001

Octal: 230451

Duodecimal: 39261

Hexadecimal: 13129

Square: 6102890641

Square Root: 279.50134167835404

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

E.g.f. A(x) satisfies: A'(x) = 1/(1 - A(A(x))). A210949

Primes of the form 4·k² - 10·k + 7 with k positive. A73337

a(0)=0, a(1)=2, a(n) = smallest prime > a(n-1)+a(n-2). A55502

Prime numbers of the form 5^k +- 4 for k >= 1. A144233

Row sums of A014621. A14622

Number of 2 X 2 matrices having all terms in {1,...,n} and even determinant. A211064

Square array T(n,k), n >= 1, k >= 1, read by antidiagonals, where T(n,k) = ∑_{1 <= x₁, x₂, ..., x_k <= n} n/gcd(x₁, x₂, ..., x_k, n). A372968

Sieve performed by successive iterations of steps where step m is: keep m terms, remove the next 3 and repeat; as m = 1,2,3,.. the remaining terms form this sequence. A112561

Positive solutions of Monkey and Coconuts Problem for the classic case (5 sailors, 1 coconut to the monkey): a(n) = 15625·n - 4 for n >= 1. A254029

Shifts left under exponential reversion. A67146