number_format_i18n( float $number, int $decimals )

function number_format_i18n( $number, $decimals = 0 ) {
	global $wp_locale;

	if ( isset( $wp_locale ) ) {
		$formatted = number_format( $number, absint( $decimals ), $wp_locale->number_format['decimal_point'], $wp_locale->number_format['thousands_sep'] );
	} else {
		$formatted = number_format( $number, absint( $decimals ) );
	}

	/**
	 * Filters the number formatted based on the locale.
	 *
	 * @since WP-2.8.0
	 * @since WP-4.9.0 The `$number` and `$decimals` arguments were added.
	 *
	 * @param string $formatted Converted number in string format.
	 * @param float  $number    The number to convert based on locale.
	 * @param int    $decimals  Precision of the number of decimal places.
	 */
	return apply_filters( 'number_format_i18n', $formatted, $number, $decimals );
}