The LaTeX command for mathbb N (ℕ) is \mathbb{N} (natural numbers).
\mathbb{N}Writing a paper? The table generator and the BibTeX cleaner are one click away, no account.
Write \mathbb{N} inside math mode, that is between $…$ for inline math or in a \[ … \] or equation block for display math. This symbol needs the amssymb package, so add \usepackage{amssymb} to your preamble.
Set notation lives in math mode: write $\mathbb{N}$, even in the middle of a sentence. With unicode-math under XeLaTeX or LuaLaTeX, typing ℕ in a formula gives the same symbol. Not to be confused with \mathbb{R} (ℝ).
$A \mathbb{N} B$Open this example in the live preview: it renders as you type, with no compiler and no signup.
\mathbb{R} (ℝ): real numbers\mathcal{N} (𝒩): normal / Gaussian distribution\mathds{1} (𝟙): indicator function / characteristic function\emptyset\varnothing\mathbb{Z}\mathbb{Q}\mathbb{R}\mathbb{C}\mathbb{F}^\complement\bigcap\bigcup\bigsqcup\uplus\biguplus\mathcal{P}Set symbols in LaTeX: the full table or search all 350+ LaTeX symbols.
Use \mathbb{N} in math mode after adding \usepackage{amssymb} to your preamble. For example, $A \mathbb{N} B$.
It comes from the amssymb package: add \usepackage{amssymb} to your preamble.