Nombre

7

7 — Seven

7 is a prime, odd, a calendar year.

Seven is the fourth prime number and the lowest natural number that cannot be represented as the sum of the squares of three integers. It appears repeatedly across cultures: seven days of the week, seven wonders of the ancient world, seven deadly sins.

Sources https://en.wikipedia.org/wiki/7

Cousin Prime Curated Deficient Number Happy Number Harshad / Niven Heptagonal Lucas Mersenne Prime Narcissistic / Armstrong Prime Recamán's Sequence Sexy Prime Squarefree Twin Prime

Propriétés

Parité: Impair
Nombre de chiffres: 1
Somme des chiffres: 7
Racine numérique: 7
Palindrome: Oui
Suite de Recamán: a(5) = 7
Nombre de diviseurs: 2
σ(n) — somme des diviseurs: 8

Primalité

7 is prime. It has exactly two divisors: 1 and itself.

Diviseurs et multiples

All divisors (2)

1 · 7

Aliquot sum (sum of proper divisors): 1

Factor pairs (a × b = 7)

1 × 7

First multiples

7 · 14 · 21 · 28 · 35 · 42 · 49 · 56 · 63 · 70

Représentations

En lettres: seven
Ordinal: 7th
Chiffre romain: VII
Binaire: 111
Octal: 7
Hexadécimal: 0x7
Base64: Bw==

Aussi vu comme

Prime neighborhood

Adjacent primes:

Previous prime: 5 (gap of 2)
Next prime: 11 (gap of 4)

Pair status: twin with 5, cousin with 11.

ASCII character

As an ASCII codepoint, 7 is BEL (bell). ASCII control character.

Hex color

#000007

RGB(0, 0, 7)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.7.

Address: 0.0.0.7
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.0.7

Unspecified address (0.0.0.0/8) — "this network" placeholder.